diff --git a/20201201/main.go b/20201201/main.go
new file mode 100644
index 0000000..789394e
--- /dev/null
+++ b/20201201/main.go
@@ -0,0 +1,46 @@
+package main
+
+func main() {
+
+}
+
+func isEcho(s string) bool {
+	if s == "" {
+		return false
+	}
+	l := 0
+	r := len(s) - 1
+	for r >= l {
+		if s[l] != s[r] {
+			return false
+		}
+		l++
+		r--
+	}
+	return true
+}
+
+func isAlmostEcho(s string) bool {
+	if s == "" {
+		return false
+	}
+	l := 0
+	r := len(s) - 1
+	for r >= l {
+		if s[l] != s[r] && !isEcho(removeIndex(l, s)) && !isEcho(removeIndex(r, s)) {
+			return false
+		}
+		l++
+		r--
+	}
+	return true
+}
+
+func removeIndex(index int, s string) string {
+	if index >= len(s) {
+		return s
+	}
+	ret := []rune(s)
+	ret = append(ret[0:index], ret[index+1:]...)
+	return string(ret)
+}
diff --git a/20201201/main_test.go b/20201201/main_test.go
new file mode 100644
index 0000000..51a055b
--- /dev/null
+++ b/20201201/main_test.go
@@ -0,0 +1,121 @@
+package main
+
+import "testing"
+
+func Test_isEcho(t *testing.T) {
+	type args struct {
+		s string
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			"test1",
+			args{"aba"},
+			true,
+		},
+		{
+			"test2",
+			args{"abca"},
+			false,
+		},
+		{
+			"test3",
+			args{"abcba"},
+			true,
+		},
+		{
+			"test4",
+			args{""},
+			false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := isEcho(tt.args.s); got != tt.want {
+				t.Errorf("isEcho() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_isAlmostEcho(t *testing.T) {
+	type args struct {
+		s string
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			"test1",
+			args{"aba"},
+			true,
+		},
+		{
+			"test2",
+			args{"abca"},
+			true,
+		},
+		{
+			"test3",
+			args{"abcba"},
+			true,
+		},
+		{
+			"test4",
+			args{""},
+			false,
+		},
+		{
+			"test5",
+			args{"abcbba"},
+			true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := isAlmostEcho(tt.args.s); got != tt.want {
+				t.Errorf("isAlmostEcho() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_removeIndex(t *testing.T) {
+	type args struct {
+		index int
+		s     string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			"test1",
+			args{0, "ab"},
+			"b",
+		},
+		{
+			"test2",
+			args{0, ""},
+			"",
+		},
+		{
+			"test3",
+			args{1, "abc"},
+			"ac",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := removeIndex(tt.args.index, tt.args.s); got != tt.want {
+				t.Errorf("removeIndex() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}