#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <cctype>

using namespace std;

int main(){

    int A,B;
    cin >> A >> B;
    string S;
    cin >> S;

    for (int i = 0; i < S.length(); i++){
        if (i == A){
            if(S[i] != '-'){
                //printf("%d : haihun\n", i);
                puts("No");
                return 0;
            }
        }else{
            if (isdigit(S[i])){
                continue;
            }else{
                //printf("%d : not digit\n", i);
                puts("No");
                return 0;
            }
        }
    }

    puts("Yes");

    return 0;
}
