#include <bits/stdc++.h>
using namespace std;
char s[12];
int main() {
  int a, b;
  cin >> a >> b;
  cin >> s;
  int cnt1 = 0;
  int cnt2 = 0;
  int cnt3 = 0;
  for (int k = 0; k < a; ++k) {
    if (s[k] > '0' && s[k] <= '9') {
      cnt1++;
    }
  }
  if (s[a] == '-') {
    cnt2++;
  }
  for (int k = a + 1; k <= a + b; ++k) {
    if (s[k] > '0' && s[k] <= '9') {
      cnt3++;
    }
  }
  if (cnt1 == a && cnt2 == 1 && cnt3 == b) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
