#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, i, n, t = 0;
  string s;
  cin >> a >> b;
  cin >> s;
  n = s.size();
  if ((n == (a + b + 1)) && (s[a + 1] == '-')) {
    for (i = 0; i < n; i++) {
      if (i == (a + 1)) {
        continue;
      }
      if (s[i] == '0' || s[i] == '1' || s[i] == '2' || s[i] == '3' ||
          s[i] == '4' || s[i] == '5' || s[i] == '6' || s[i] == '7' ||
          s[i] == '8' || s[i] == '9')
        t++;
    }
    if (t == (n - 1))
      cout << "Yes" << endl;
    else
      cout << "No" << endl;
  } else
    cout << "No" << endl;
  return 0;
}
