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 C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int main(void){

  int a,b;
  scanf("%d %d", &a, &b);
	char s[a+b+2];
	scanf("%s", s);
	int flag = 1;
	for (int i = 0; i < a+b+1; i++) {
		if (i == a) {
			if (s[i] != '-') {
				flag = 0;
				break;
			}
		} else {
			if (s[i] < '0' || s[i] > '9') {
				flag = 0;
				break;
			}
		}
	}
	if (flag == 1) {
		printf("Yes\n");
	} else {
		printf("No\n");
	}

  return 0;
}