https://programmers.co.kr/learn/courses/30/lessons/12916
import Foundation
func solution(_ s:String) -> Bool {
var count = 0
var count2 = 0
for i in Array(s.lowercased()) {
if i == "p" {
count += 1
} else if i == "y" {
count2 += 1
}
}
return count - count2 == 0 ? true : false
}