#include<bits/stdc++.h>
using namespace std;
int main(){
  int a,b; cin >> a >> b;
  bool f = true;
  for(int i = 0; i < a + b + 1; ++i){
    char c; cin >> c;
    f &= (i==a?c=='-':isdigit(c));
  }
  if(f)cout << "Yes" << endl;
  else cout << "No" << endl;
  return 0;
}