#include <bits/stdc++.h>
using namespace std;

int main() {
  int a, b;
  string S;
  cin >> a >> b >> S;
  
  for(int i = 0; i < a; i++){
    if(S[i] > 9 && S[i] < 0){
      cout << "No" << endl;
    }
  }
  
  if(S[a] != '-'){
    cout << "No" << endl;
  }
  
  for(int i = a+1; i <a+b;i++){
    if(S[i] > 9 && S[i] < 0){
      cout << "No" << endl;
    }
  }
  else{
    cout << "Yes" << endl;
  }
}