diff --git a/2020/day10-adapter-array.py b/2020/day10-adapter-array.py
new file mode 100644
index 0000000..b140a53
--- /dev/null
+++ b/2020/day10-adapter-array.py
@@ -0,0 +1,42 @@
+import copy
+import itertools
+from typing import List
+
+
+def main(filename: str, expected_part_1: int = None, expected_part_2: int = None):
+    print(f"\n+ Running on {filename}")
+    with open(filename) as f:
+        jolts = sorted(map(int, f.read().strip().split("\n")))  # type: List[int]
+
+    jolts.append(jolts[-1] + 3)
+
+    counter_part_1 = solve_part_1(jolts)
+    counter_part_2 = 0
+
+    print(f"1. Found {counter_part_1}")
+    if expected_part_1:
+        assert expected_part_1 == counter_part_1
+
+    print(f"2. Found {counter_part_2}")
+    if expected_part_2:
+        assert expected_part_2 == counter_part_2
+
+
+def solve_part_1(jolts):
+    diffs = count_diffs(jolts)
+    return diffs[1] * diffs[3]
+
+
+def count_diffs(jolts):
+    diffs = {1: 0, 2: 0, 3: 0}
+    previous = 0
+    for jolt in jolts:
+        diffs[jolt - previous] += 1
+        previous = jolt
+    return diffs
+
+
+if __name__ == "__main__":
+    main("inputs/day10-test1", 35, 8)
+    main("inputs/day10-test2", 220, 19208)
+    main("inputs/day10", 2450)
diff --git a/2020/inputs/day10 b/2020/inputs/day10
new file mode 100644
index 0000000..c472cf1
--- /dev/null
+++ b/2020/inputs/day10
@@ -0,0 +1,104 @@
+2
+49
+78
+116
+143
+42
+142
+87
+132
+86
+67
+44
+136
+82
+125
+1
+108
+123
+46
+37
+137
+148
+106
+121
+10
+64
+165
+17
+102
+156
+22
+117
+31
+38
+24
+69
+131
+144
+162
+63
+171
+153
+90
+9
+107
+79
+7
+55
+138
+34
+52
+77
+152
+3
+158
+100
+45
+129
+130
+135
+23
+93
+96
+103
+124
+95
+8
+62
+39
+118
+164
+172
+75
+122
+20
+145
+14
+112
+61
+43
+141
+30
+85
+101
+151
+29
+113
+94
+68
+58
+76
+97
+28
+111
+128
+21
+11
+163
+161
+4
+168
+157
+27
+72
diff --git a/2020/inputs/day10-test1 b/2020/inputs/day10-test1
new file mode 100644
index 0000000..cd1b40b
--- /dev/null
+++ b/2020/inputs/day10-test1
@@ -0,0 +1,11 @@
+16
+10
+15
+5
+1
+11
+7
+19
+6
+12
+4
\ No newline at end of file
diff --git a/2020/inputs/day10-test2 b/2020/inputs/day10-test2
new file mode 100644
index 0000000..be5c492
--- /dev/null
+++ b/2020/inputs/day10-test2
@@ -0,0 +1,31 @@
+28
+33
+18
+42
+31
+14
+46
+20
+48
+47
+24
+23
+49
+45
+19
+38
+39
+11
+1
+32
+25
+35
+8
+17
+7
+9
+4
+2
+34
+10
+3
\ No newline at end of file