diff --git a/2022/rust/inputs/day25.txt b/2022/rust/inputs/day25.txt
new file mode 100644
index 0000000..5476bec
--- /dev/null
+++ b/2022/rust/inputs/day25.txt
@@ -0,0 +1,132 @@
+1--20
+1-00==1-1==
+12011==21020=-2021-
+101--=11
+22-=02=
+112=12-222
+10=-0-=10
+202-1-20=01-10-2
+11==
+122==1=100-
+1====2==121--=1
+1=-02-=011-2=2-00=00
+1000=2
+12-
+201=2-1-1=02--=1=1
+1=01-1=-1=012-2-=
+1=1=
+11102
+10=
+2-=--2=2=-==11-11
+2=02
+10-1-00=0-20
+1-0=11=
+2=1=0=1022=-
+1==1--2-=02=
+1=12-2
+200-
+20=02-211=11=
+1==12=-0-
+1=1-0101=-1
+2=21000-22
+1--1=11-2-=1--211-
+2-=101=-
+1-20210-0-1=101=1
+1===1===-
+211=2-0==
+21===1==0
+10
+2=0-1=110221-2-2
+1001220120=-=
+10=21=0-=--=21-=
+1=0=1-2-0
+21-0===21=2100-02
+1=-=0-0-12=-0--202=
+101200-111--10-=-
+2201==0--=-
+12-02201-====-=
+2-1220-
+10-
+2=00-2-2
+22-
+1=01--==
+202-11-=02-22-02
+2-0=1=1=-1-0-2=-0=
+1=01-1=2=11=10
+1-011
+1-0-1
+11000=--0122-
+1=-==2=101
+1=10-0=110--1
+200=-21-
+222==20=22121-==2
+11=
+1-2=22-0212=1
+2=--2=02
+1=0-2=1-0==0=-=1-1
+101
+2=1=1=1202222010=1
+1-=0
+1-02
+1=21=2==2=2
+11-10-=20==1
+1002=---012=1
+222
+1==-1=
+1-212=-=2
+212=--0
+1-0=2-121=-11
+11211011=--
+2-
+12=
+22-202
+2=20=-1220=10=---
+11=--0122==20-121
+200=
+2=220=
+1=00=001121=1-00-
+100210222
+2-2==1
+220
+2-==-1=10
+1=212=212=0=-2200
+201--0=12-101
+1==0000=1=0
+2===
+121-021220=022
+1=====--10201111-0
+22=2122
+1=2110=2-21022
+120=1=1-2002-12211
+221200
+110--
+100120=1
+22
+2-==----2020=
+10=-
+11==-0=2-==0==2=
+1===122=0=
+21==-1
+1-11-21--1
+1011=1-0---=11=0
+2=01=21-0
+12=0=1-1==00010-2-
+20-20--011
+10=21212===-011=2=1
+1-112110021-12220
+1==022=112-2
+1-=0-
+1=
+1=1
+21212=211110--2
+11-2-212=--02=0120
+1-=1--=010=
+2-11221101=-2=2=2=
+2=
+1=021
+1===0020-1==
+1022212
+1-=221=
+122-2-1-2--200=
+1-00-10
+102-20=-02--=201=
diff --git a/2022/rust/src/main.rs b/2022/rust/src/main.rs
index aea977e..a4f8fe4 100644
--- a/2022/rust/src/main.rs
+++ b/2022/rust/src/main.rs
@@ -26,5 +26,6 @@ fn main() {
     // solutions::day21::run();
     // solutions::day22::run();
     // solutions::day23::run();
-    solutions::day24::run();
+    // solutions::day24::run();
+    solutions::day25::run();
 }
diff --git a/2022/rust/src/solutions/day25.rs b/2022/rust/src/solutions/day25.rs
new file mode 100644
index 0000000..88ff65d
--- /dev/null
+++ b/2022/rust/src/solutions/day25.rs
@@ -0,0 +1,87 @@
+#![allow(dead_code)]
+use crate::utils;
+
+
+pub fn run() -> () {
+    let data = utils::read_lines(utils::Source::Day(25));
+
+    println!("Day 25");
+    println!("Part 1: {}", solve1(&data));
+}
+
+
+fn snafu2dec<T: AsRef<str>>(str: T) -> i64 {
+    str.as_ref().chars()
+        .fold(0, |acc, char| {
+            let num = match char {
+                '0' => 0,
+                '1' => 1,
+                '2' => 2,
+                '-' => -1,
+                '=' => -2,
+                _ => unreachable!(),
+            };
+            acc * 5 + num
+        })
+}
+
+fn dec2snafu(mut num: i64) -> String {
+    let mut snafu = String::new();
+    while num > 0 {
+        let rem = num % 5;
+        num = num / 5 + if rem > 2 { 1 } else { 0 };
+        snafu.push(match rem {
+            0 => '0',
+            1 => '1',
+            2 => '2',
+            3 => '=',
+            4 => '-',
+            _ => unreachable!(),
+        });
+    }
+    if snafu.is_empty() { snafu.push('0'); }
+    snafu.chars().rev().collect()
+}
+
+
+fn solve1<T: AsRef<str>>(data: &[T])-> String {
+    dec2snafu(data.iter().map(snafu2dec).sum())
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    static DATA: &[&str] = &[
+        "1=-0-2",
+        "12111",
+        "2=0=",
+        "21",
+        "2=01",
+        "111",
+        "20012",
+        "112",
+        "1=-1=",
+        "1-12",
+        "12",
+        "1=",
+        "122",
+    ];
+
+    #[test]
+    fn part1() {
+        assert_eq!(1, snafu2dec("1"));
+        assert_eq!(5, snafu2dec("10"));
+        assert_eq!(2022, snafu2dec("1=11-2"));
+        assert_eq!(12345, snafu2dec("1-0---0"));
+        assert_eq!(314159265, snafu2dec("1121-1110-1=0"));
+        assert_eq!("1", dec2snafu(1));
+        assert_eq!("10", dec2snafu(5));
+        assert_eq!("1=11-2", dec2snafu(2022));
+        assert_eq!("1-0---0", dec2snafu(12345));
+        assert_eq!("1121-1110-1=0", dec2snafu(314159265));
+        // test input
+        assert_eq!("2=-1=0", solve1(DATA));
+    }
+}
diff --git a/2022/rust/src/solutions/mod.rs b/2022/rust/src/solutions/mod.rs
index 64278a7..d5bc06f 100644
--- a/2022/rust/src/solutions/mod.rs
+++ b/2022/rust/src/solutions/mod.rs
@@ -22,3 +22,4 @@ pub mod day21;
 pub mod day22;
 pub mod day23;
 pub mod day24;
+pub mod day25;
diff --git a/2022/rust/src/utils.rs b/2022/rust/src/utils.rs
index 4b5b02e..7c48c9e 100644
--- a/2022/rust/src/utils.rs
+++ b/2022/rust/src/utils.rs
@@ -13,7 +13,7 @@ pub fn read_lines(source: Source) -> Vec<String> {
     let path = match source {
         Source::Scratch => "inputs/scratch.txt".to_string(),
         Source::Day(day) => {
-            assert!(1 <= day && day < 25);
+            assert!(1 <= day && day <= 25);
             format!("inputs/day{:0>2}.txt", day)
         }
     };