#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const int mod = 1e9 + 7;
const double eps = 1e-6;
bool solve(string s, int a, int b) {
  if (s.length() != a + b + 1) return false;
  for (int i = 0; i < s.length(); i++) {
    if (i == a + 1 && s[i] != '-') return false;
    if (i != a + 1 && !isdigit(s[i])) return false;
  }
  return true;
}
int main() {
  int a, b;
  string s;
  cin >> a >> b >> s;
  solve(s, a, b) ? cout << "Yes" << endl : cout << "No" << endl;
  return 0;
}
