#include <bits/stdc++.h>
using namespace std;
long long int a, b, s;
int main() {
  string s;
  cin >> a >> b;
  cin >> s;
  if (s[a] != '-') cout << "No" << endl;
  return 0;
  s[a] = '1';
  for (int i = 0; i <= a + b; i++)
    if (s[i] < '0' || s[i] > '9') cout << "No" << endl;
  return 0;
  cout << "Yes" << endl;
  return 0;
}
