#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  string S;
  cin >> A >> B;
  cin >> S;
  for (int i = 0; i < A; i++) {
    if ('0' <= S[i] && S[i] <= '9') {
      ;
    } else {
      cout << "No";
      return 1;
    }
  }
  if (S[A] == '-') {
    ;
  } else {
    cout << "No";
    return 1;
  }
  for (int i = A + 1; i < A + B + 1; i++) {
    if ('0' <= S[i] && S[i] <= '9') {
      ;
    } else {
      cout << "No";
      return 1;
    }
  }
  cout << "Yes";
  return 0;
}
