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