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>
#include <string.h>
#include <math.h>
typedef long long ll;

int main()
{
	int A, B, flag = 0;
	char S[21];
	scanf("%d %d", &A, &B);
	scanf("%s", S);

	for (int i = 0; i <= A + B; i++) {
		if (i == A) {
			if (S[i] != '-') {
				flag = 1;
				break;
			}
		} else {
			if (!isdigit(S[i])) {
				flag = 1;
				break;
			}
		}
	}

	if (flag == 0)
		printf("Yes\n");
	else
		printf("No\n");

	return 0;
}