#include <bits/stdc++.h>
const long double PI = (acos(-1));
using namespace std;
int ctoi(char c) {
  switch (c) {
    case '0':
      return 0;
    case '1':
      return 1;
    case '2':
      return 2;
    case '3':
      return 3;
    case '4':
      return 4;
    case '5':
      return 5;
    case '6':
      return 6;
    case '7':
      return 7;
    case '8':
      return 8;
    case '9':
      return 9;
    default:
      return 0;
  }
}
int main() {
  int a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  bool ans = false;
  bool boo1 = false;
  bool boo2 = false;
  bool boo3 = false;
  for (int i = 0; i < a; i++) {
    if (ctoi(s[i]) >= 0 && ctoi(s[i]) <= 9) {
      boo1 = true;
    }
  }
  if (s[a] == '-') {
    boo2 = true;
  }
  for (int j = a + 1; j < s.size(); j++) {
    if (ctoi(s[j]) >= 0 && ctoi(s[j]) <= 9) {
      boo3 = true;
    }
  }
  if (boo1 && boo2 && boo3) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}
