func divideArray(nums []int) bool {
pairs := make(map[int]int)
for _, n := range nums {
c, f := pairs[n]
if !f {
pairs[n] = 1
} else {
pairs[n] = c + 1
}
}
for _, v := range pairs {
if v%2==1 {
return false
}
}
return true
}