func areEqual(a, b int, x, y int) bool {
c, z := utils.GCD(a, b), utils.GCD(x, y)
if c == 0 || z == 0 {
return c == z
}
return a/c == x/z && b/c == y/z
}
func E5() int {
res := 1
for i := 1; i <= 20; i++ {
res *= i / utils.GCD(res, i)
}
return res
}
func E33() int {
n, d := 1, 1
for i := 10; i < 100; i++ {
for j := i + 1; j < 100; j++ {
if i%10 == 0 || j%10 == 0 {
continue
}
k, l := 1, 1
if i/10 == j/10 && areEqual(i, j, i%10, j%10) {
k, l = i%10, j%10
}
if i/10 == j%10 && areEqual(i, j, i%10, j/10) {
k, l = i%10, j/10
}
if i%10 == j/10 && areEqual(i, j, i/10, j%10) {
k, l = i/10, j%10
}
if i%10 == j%10 && areEqual(i, j, i/10, j/10) {
k, l = i/10, j/10
}
n *= k
d *= l
}
}
return d / utils.GCD(n, d)
}