#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int a, b, c;
  cin >> a >> b;
  cin >> s;
  c = 0;
  for (int i = 0; i < a; i++) {
    if ('0' <= s[i] <= '9')
      ;
    else
      c++;
  }
  if (s[a] == '-')
    ;
  else
    c++;
  for (int i = a + 1; i < a + b + 1; i++) {
    if ('0' <= s[i] <= '9')
      ;
    else
      c++;
  }
  if (c > 0)
    cout << "No" << endl;
  else
    cout << "Yes" << endl;
}
