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

int main() {
  int a,b;
  string s[12];
  cin >> a >> b;
  cin >> s;
  for(int i = 0; i < a + b + 1; i ++){
    	if(i == a && s[i] == "-"){
        	continue;
        }
      	else if(s[i] >= "0" && s[i] <= "9" ){
        	continue;
        }
    	else{
        	break;
        }
  }
  if(i == a + b + 1){
   cout << "Yes" << endl;
  }
  else{
  	cout << "No" << endl;
  }
}