diff --git a/2022/day25.py b/2022/day25.py
index dbb8408..553141a 100644
--- a/2022/day25.py
+++ b/2022/day25.py
@@ -1,3 +1,29 @@
 # -*- encoding: utf-8 -*-
 
 import sys
+
+lines = sys.stdin.read().splitlines()
+
+coeffs = {"2": 2, "1": 1, "0": 0, "-": -1, "=": -2}
+
+
+def snafu2number(number: str) -> int:
+    value = 0
+    for c in number:
+        value *= 5
+        value += coeffs[c]
+    return value
+
+
+def number2snafu(number: int) -> str:
+    values = ["0", "1", "2", "=", "-"]
+    res = ""
+    while number > 0:
+        mod = number % 5
+        res = res + values[mod]
+        number = number // 5 + int(mod >= 3)
+    return "".join(reversed(res))
+
+
+answer_1 = number2snafu(sum(map(snafu2number, lines)))
+print(f"answer 1 is {answer_1}")
diff --git a/2022/inputs/day25.txt b/2022/inputs/day25.txt
index e69de29..547e6b0 100644
--- a/2022/inputs/day25.txt
+++ b/2022/inputs/day25.txt
@@ -0,0 +1,124 @@
+21-0==1=-0
+102211-220011-----
+1=2=111=10=-
+12-2=022=2
+1=--=11
+12-2211000=0011-0-
+1=1-
+2=0-10-=21-2
+1210-
+2=1-=
+1=0=12=2112--11=
+2--211=200
+20-02-20
+12=12=0=0=1
+22===21=-0102-012=
+1--=-121
+1=02=2-=
+12-0-20
+2=---=0102--00=22
+1=2==0=2=
+11-1112
+2--012
+12=12=--212-0-==-02
+1=220
+20===1
+2210-02=12-022-=1-
+22--1-==1
+211-1=1=0-==1
+10
+1-1-02
+1=-2==-0=21
+1=102
+20121021
+1=2=22=001200-==1020
+10211-1-20--10-1=
+1222==1--=1--11-=
+11211211
+1=101-20=
+1=1-11=0=000
+1=-=101
+2
+1000-2
+1==0=210=1=21222-=2
+1=1==2-
+2--020=2=2===-
+2-
+2=0
+222101=22=-21=11
+2=
+121201-0-20-2-=11=
+10=
+1212=20=2=-=-1--1
+2-20-=212=01
+1=1--00--0=12=-00
+22--
+22
+22===1=-0-22-
+111-=
+2-111=0021=2
+200=22-=12-2=
+1==-=1=0
+1--=02-0002=
+1=-=2-2=2-
+2=2222220=2==001
+1=00==11=-20-=2-2
+1---0=-=
+1-0==10-=22001
+1=02=02-1=0111
+1-=010-21-=21==02
+10200-2=-=20120-2
+1=-
+10=122-
+210-1=-=2011-0--1
+2==-1=20
+1=-=101-20=221-1
+210
+1-=-==-0-=02=---
+1-=1=-=12=0
+1-=0---12-0=
+210-==1021=010=1
+1=-212
+11=1=-=2211=101222-
+2=-==--=2
+1=11-200--=
+1120-
+11=-0=221=0101=
+11-1=-
+1-12-2=0
+1012-22=1-
+20-122=-1=
+1-100=0=101-0
+20-1=1=0
+1102=
+21
+10=20=11
+1-=2001
+1-20=12-0221102-==
+1-1--010100=-1=
+221002==2102-2=1
+2012=121-22
+110222002=01
+212102-1=1=-211
+210-=12
+1=-1-0101=1-12
+12--21=1
+10=-12
+100-122211=--2=
+101102001
+11011=-
+211-0=-=0
+1-2=01-1=
+1-022-=00000
+2==-0==2=--00=
+10=--2000==
+1---=--1-110-02
+11-012
+2==-2210-0
+212
+22-=-12111
+2--=
+2=2=12-100
+10-12===0-
+1==0=0=22012201
+211-1--22
diff --git a/2022/tests/day25.txt b/2022/tests/day25.txt
index e69de29..027aeec 100644
--- a/2022/tests/day25.txt
+++ b/2022/tests/day25.txt
@@ -0,0 +1,13 @@
+1=-0-2
+12111
+2=0=
+21
+2=01
+111
+20012
+112
+1=-1=
+1-12
+12
+1=
+122