#include <bits/stdc++.h>
using namespace std;
int main(){
  int A,B;
  string S;
  cin >> A >> B >> S;
  bool res = true;
  for (int i = 0; i < S.size(); i++) if (i == A && S[i] != '-' || i != A && !isdigit(S[i])) res = false;
  cout << (res ? "Yes" : "No");
}