Problem:
Score : 200 points

Problem Statement

The postal code in Atcoder Kingdom is A+B+1 characters long, its (A+1)-th character is a hyphen -, and the other characters are digits from 0 through 9.

You are given a string S. Determine whether it follows the postal code format in Atcoder Kingdom.

Constraints

1≤A,B≤5

|S|=A+B+1

S consists of - and digits from 0 through 9.

Input

Input is given from Standard Input in the following format:

A B
S

Output

Print Yes if S follows the postal code format in AtCoder Kingdom; print No otherwise.

Sample Input 1

3 4
269-6650

Sample Output 1

Yes

The (A+1)-th character of S is -, and the other characters are digits from 0 through 9, so it follows the format.

Sample Input 2

1 1
---

Sample Output 2

No

S contains unnecessary -s other than the (A+1)-th character, so it does not follow the format.

Sample Input 3

1 2
7444

Sample Output 3

No

Solution in Kotlin (1.0.0) (judge verdict: Accepted)

import java.util.*

fun main(args: Array<String>) {
  val sc = Scanner(System.`in`)
  val a = sc.nextInt()
  val b = sc.nextInt()
  val s = sc.next()

  var ans = true
  if (s.length != a + b + 1) ans = false

  for (i in 0 until a) {
    if ('0' <= s.get(i) && s.get(i) <= '9') {
    } else {
      ans = false 
    }
  }
  if (s.get(a) != '-') ans = false
  for (i in a + 1 until a + b + 1) {
    if ('0' <= s.get(i) && s.get(i) <= '9') {
    } else {
      ans = false
    }
  }

  var str = "No"
  if (ans) str = "Yes"

  println(str)
}