#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  char s[11];
  bool c = false;
  cin >> a >> b;
  cin >> s;
  if (s[a] == '-' && s[a + b + 1] == NULL) {
    s[a] = '0';
    for (int i = 0; i < 11; i++) {
      if (s[i] >= '0' && s[i] <= '9') {
        c = true;
      } else {
        cout << "No";
        break;
      }
    }
  } else {
    cout << "No";
  }
  if (c == true) {
    cout << "Yes";
  }
  return 0;
}
