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

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