#include <bits/stdc++.h>
using namespace std;
int INF = 100100101;
bool func(char c) {
  if (c >= '0' && c <= '9')
    return true;
  else
    return false;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  for (int i = 0; i < (a); ++i) {
    if (func(s[i]) == false) {
      cout << "No" << endl;
      return 0;
    }
  }
  if (s[a] != '-') {
    cout << "No" << endl;
    return 0;
  }
  for (int i = b; i < s.length(); i++) {
    if (func(s[i]) == false) {
      cout << "No" << endl;
      return 0;
    }
  }
  cout << "Yes" << endl;
}
