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: Wrong Answer)

#include <stdio.h>
int main()
{
    int a,b,c,d,i=1,e=0,f=1,g=0,ret;
    scanf("%d %d",&a,&b);
    ret=scanf("%d-%d",&c,&d);
    if(ret!=2)
    {
        printf("No");
    }
    do
    {
        i=i*10;
        e++;
    }while(i<c);
    do
    {
        f=f*10;
        g++;
    }while(f<d);
    if(e==a&&g==b)
    {
        printf("Yes");
    }
    else
        printf("No");
    return 0;
}