#include <iostream>
#include <algorithm>
#include <cmath>
#include <limits>
#include <vector>
#include<cstdio>
#include<bits/stdc++.h>
using namespace std;
using ll =long long;

int main (void) {
  int A,B;
  string S;
  cin >> A>>B;
  cin>>S;
  if(S[A+1] !="-" || S.size()==A+B+1){
    cout << "No";
    break;
  }
  else{
    cout << "Yes"
  }
}