#include <bits/stdc++.h>
using namespace std;
 
int main() {
  int A,B;
  string S,X;
  
  cin >> A >> B >> S;
  
  X = A + "-" + B; 
  if(X[A] == "-"){
  	if(X.size() == A+B){
    	cout << "Yes" << endl;
    }
  }
  cout << "No" << endl; 
}