#include <bits/stdc++.h>
using namespace std;
int A, B;
string S;
bool ans = true;
void solve() {
  for (int i = 0; i < A; ++i) {
    if (i == A + 1) {
      if (S[i] != '-') {
        ans = false;
      }
    } else {
      for (int j = 0; j < 10; ++j) {
        if (S[i] != j) {
          ans = false;
        }
      }
    }
  }
  if (ans) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}
int main() {
  cin >> A >> B;
  cin >> S;
  solve();
  return 0;
}
