#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  cin >> A >> B;
  string S;
  cin >> S;
  string strnum = "0123456789";
  string stralph = "abcdefghijklmnopqrstuvwxyz";
  string strAlph = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  for (int i = 0; i < A + B + 1; i++) {
    if (i == A && S[i] == '-') {
      continue;
    }
    if ((int)S[i] >= (int)strnum[0] && (int)S[i] <= (int)strnum[9]) {
      continue;
    } else {
      return 1;
    }
    cout << "No" << endl;
    return 0;
  }
  cout << "Yes" << endl;
  return 0;
}
