#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, j, k, n, m, l, f, x, y, z;
  string s;
  cin >> x >> y >> s;
  string t = "Yes";
  n = s.size();
  for (i = 0; i < n; i++) {
    if (i == x) {
      if (s[i] != '-') {
        t = "No";
        break;
      }
      continue;
    }
    if (!(s[i] >= '0' && s[i] <= '9')) {
      cout << (s[i] >= '0' && s[i] <= '9') << endl;
      t = "No";
      break;
    }
  }
  cout << t << endl;
}
