#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  string c;
  int count = 0;
  cin >> a >> b >> c;
  for (int i = 0; i < a + b; i++) {
    if (c[i] == '0' || c[i] == '1' || c[i] == '2' || c[i] == '3' ||
        c[i] == '4' || c[i] == '5' || c[i] == '6' || c[i] == '7' ||
        c[i] == '8' || c[i] == '9') {
      count++;
    }
  }
  if (c[a] == '-') {
    if (c.length() == a + b + 1) {
      if (count == a + b - 1) {
        cout << "Yes" << endl;
      }
    }
  } else {
    cout << "No" << endl;
  }
}
