diff --git a/day25/input b/day25/input
new file mode 100644
index 0000000..7a9cc20
--- /dev/null
+++ b/day25/input
@@ -0,0 +1,125 @@
+2-=0102020-02
+1-02202=-1=-2==
+1==00-101-=0-
+211012=12222
+112-20
+11==0020-=20-=0=12=
+122-22110
+1==00-1201112==--=
+1-10==11=
+10=0=110-2
+1111=000=2001=211=
+22-21===0=-
+2=022
+11=-0100===
+10=10--==-0
+12=01-1
+12-01--20121-2-=0-1
+22-222--022-0-=01-
+12-1
+2-=2=02-1=
+2210
+1=2=0211
+10=01=001-01
+2
+201=-1
+11---10
+1=-0=
+1=-021
+1-2=02012111=01=-100
+1101=20=
+20-1-
+2-1020---
+2=121=0=10=
+1022-22211112=-1
+2-1-
+210--==00
+12=1122-10
+1=2222=2-=21=0
+1=021=
+1=10-1201
+1=1
+1-=-==0201-=1=0
+22=2=211-0-1=2=1
+1=21-=002111
+102112=10021
+1===-111-=2001122
+10--
+1-
+1-2-2
+11-1-1-02-
+1=20--=1=0101-1001
+12012-
+1220-1--00
+1=2=1-
+12-0=2022=0100-1
+12=2-=-=221==2=
+2-2-
+1=-1-01-0=
+12---2=
+1=1=1102-==010
+10-=--200=
+1=2212=-
+12-121=-
+1===0-=20-=
+1=2020-01---112=1-
+101=00111=20=
+1=2=01=1-2==0-
+2=-100---00
+1==1=01--===0-10-
+1==-=0-20
+1=2011121=10--2
+2-=0-01-=--12102=
+200
+2==22=0002-210
+102
+1-22221
+20==00
+1-22--2-0=10=11-1
+1=12=2
+1=-12-=
+10-020-100=0=
+1-11111
+1=02-002220
+20==0120210--1
+100-121=2-2-=00=
+21
+11=-=-
+2-=1100=10102-
+112--0-2=1--=2=
+1-1==100
+1--02-0=1-
+1102-
+1-2-21-
+22=1=-000=210-12
+1=112-12-
+1====120==0
+20=2=22=22=2-=2=
+1=21201=
+2202202-20
+1=-2=-==--200101
+12010
+1--22=2--02
+102==-
+2-==1-10
+12-==12-2
+22=-11110=2-211
+1-0
+1=02=20-1=--
+1-20
+1102---10
+11=2-==2=1-
+2=2-
+2=10=2==221=01
+1--==-1==
+1011-111
+1-2-=---012-21
+1=-==0
+1=0011=11112102=
+10-0-=202
+2-----12=
+1=-2221020=01-10
+12-2201==
+1-102
+22-100=0-===
+100=0-0
diff --git a/day25/sample b/day25/sample
new file mode 100644
index 0000000..027aeec
--- /dev/null
+++ b/day25/sample
@@ -0,0 +1,13 @@
+1=-0-2
+12111
+2=0=
+21
+2=01
+111
+20012
+112
+1=-1=
+1-12
+12
+1=
+122
diff --git a/day25/sol.py b/day25/sol.py
new file mode 100644
index 0000000..52c1cdd
--- /dev/null
+++ b/day25/sol.py
@@ -0,0 +1,43 @@
+def eval(num):
+    digits = ["=-012".index(c)-2 for c in num]
+    n = 0
+    for x in digits:
+        n = n*5 + x
+    return n
+
+def tosnafu(n):
+    orig = n
+    digits = []
+    while n != 0:
+        n, d = divmod(n, 5)
+        digits.append(d)
+    print(digits)
+
+    carry = 0
+    for i in range(len(digits)):
+        d = digits[i] + carry
+        carry, d = divmod(d, 5)
+        if d > 2:
+            carry += 1
+            d -= 5
+        digits[i] = d
+    if carry:
+        digits.append(carry)
+    digits.reverse()
+    snafu = "".join("=-012"[d+2] for d in digits)
+    print(n, digits, snafu)
+    assert eval(snafu) == orig
+    return snafu
+
+            
+
+
+t = 0
+for line in open("input"):
+    n = (eval(line.strip()))
+    print(n)
+    t += n
+
+print(t)
+print(tosnafu(t))
+