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

int main(){
  int a,b;
  cin >> a >> b;
  char s[12];
  cin >> s
    
    for(int i=0;i<a;++i){
      if(!('0'<=s[i] && s[i] <='9')){ //if(!(~)) == if(Not(~))
        cout << "No" << endl;
        return 0;
      }
    }
  if(s[a] !='-'){
    cout << "No" << endl;
    return 0;
  }
for(int i=a+1;i<a+b;i++){
  if(!('0'<=s[i] && s[i] <= '9')){
    cout << "No" << endl;
    return 0;
  }
}
  cout << "Yes" << endl;
  return 0;
}
