diff --git a/2020/10/data.txt b/2020/10/data.txt
new file mode 100644
index 0000000..c472cf1
--- /dev/null
+++ b/2020/10/data.txt
@@ -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/2020/10/main.py b/2020/10/main.py
new file mode 100644
index 0000000..db3c920
--- /dev/null
+++ b/2020/10/main.py
@@ -0,0 +1,120 @@
+import copy
+
+
+def load(filename):
+	with open(filename, "r", encoding="utf-8") as f:
+		return [int(x) for x in f]
+
+
+def calc_builtin(adapters):
+	return max(adapters) + 3
+
+
+def calc_diffs(adapters):
+	wall = 0
+	builtin = calc_builtin(adapters)
+	adapters = sorted(adapters)
+	adapters.insert(0, 0)
+	adapters.append(builtin)
+	adapters += [wall, builtin]
+
+	d1 = 0
+	d2 = 0
+	d3 = 0
+	sa = sorted(adapters)
+	for x in range(0, len(sa) - 1):
+		a = sa[x]
+		b = sa[x+1]
+		d = b - a
+		if d == 1:
+			d1 += 1
+		elif d == 2:
+			d2 += 1
+		elif d == 3:
+			d3 += 1
+
+	return d1, d2, d3
+
+
+def is_compatible(a, b):
+	return abs(a - b) <= 3
+
+
+def calc_arrangements(adapters, wall, builtin):
+	return _calc(sorted(adapters), [wall], builtin)
+
+def _calc(adapters, arranged, builtin):
+	a = arranged[-1]
+	b = adapters.pop(0)
+	while is_compatible(a, b):
+		if not adapters:
+			if is_compatible(b, builtin):
+				yield arranged + [b, builtin]
+			return
+
+		cadapters = copy.deepcopy(adapters)
+		carranged = copy.deepcopy(arranged)
+		carranged.append(b)
+		yield from _calc(cadapters, carranged, builtin)
+
+		b = adapters.pop(0)
+
+
+assert calc_builtin([3, 6, 9]) == 12
+
+adapters = load("test1.txt")
+d1, _, d3 = calc_diffs(adapters)
+assert d1 == 7
+assert d3 == 5
+
+adapters = load("test2.txt")
+d1, d2, d3 = calc_diffs(adapters)
+assert d1 == 22
+assert d3 == 10
+print(d1, d2, d3)
+
+adapters = load("data.txt")
+d1, _, d3 = calc_diffs(adapters)
+print(f"1: Answer is {d1 * d3}")
+
+##############################################################################
+
+assert d1*d3 == 2450, "Task 1"
+
+adapters = load("test1.txt")
+bi = calc_builtin(adapters)
+arrangements = list(calc_arrangements(adapters, 0, bi))
+assert [0, 1, 4, 5, 6, 7, 10, 11, 12, 15, 16, 19, 22] in arrangements
+assert [0, 1, 4, 5, 6, 7, 10, 12, 15, 16, 19, 22] in arrangements
+assert [0, 1, 4, 5, 7, 10, 11, 12, 15, 16, 19, 22] in arrangements
+assert [0, 1, 4, 5, 7, 10, 12, 15, 16, 19, 22] in arrangements
+assert [0, 1, 4, 6, 7, 10, 11, 12, 15, 16, 19, 22] in arrangements
+assert [0, 1, 4, 6, 7, 10, 12, 15, 16, 19, 22] in arrangements
+assert [0, 1, 4, 7, 10, 11, 12, 15, 16, 19, 22] in arrangements
+assert [0, 1, 4, 7, 10, 12, 15, 16, 19, 22] in arrangements
+
+adapters = load("test2.txt")
+bi = calc_builtin(adapters)
+arrangements = list(calc_arrangements(adapters, 0, bi))
+assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 46, 47, 48, 49, 52] in arrangements
+assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 46, 47, 49, 52] in arrangements
+assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 46, 48, 49, 52] in arrangements
+assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 46, 49, 52] in arrangements
+assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 47, 48, 49, 52] in arrangements
+assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 46, 48, 49, 52] in arrangements
+assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 46, 49, 52] in arrangements
+assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 47, 48, 49, 52] in arrangements
+assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 47, 49, 52] in arrangements
+assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 48, 49, 52] in arrangements
+assert len(arrangements) == 19208
+
+#adapters = load("data.txt")
+#bi = calc_builtin(adapters)
+#
+#arrangements = calc_arrangements(adapters, 0, bi)
+#c = 0
+#for x in arrangements:
+#	print(x)
+#	c += 1
+#
+#print(f"2:Found {c} ways to connect.")
diff --git a/2020/10/test1.txt b/2020/10/test1.txt
new file mode 100644
index 0000000..ec4a03f
--- /dev/null
+++ b/2020/10/test1.txt
@@ -0,0 +1,11 @@
+16
+10
+15
+5
+1
+11
+7
+19
+6
+12
+4
diff --git a/2020/10/test2.txt b/2020/10/test2.txt
new file mode 100644
index 0000000..e6376dc
--- /dev/null
+++ b/2020/10/test2.txt
@@ -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