#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  string S;
  cin >> A >> B >> S;
  bool judge = false;
  for (int i = 0; i < A + B + 1; i++) {
    if (i != A &&
        (S.at(i) != '0' || S.at(i) != '1' || S.at(i) != '2' || S.at(i) != '3' ||
         S.at(i) != '4' || S.at(i) != '5' || S.at(i) != '6' || S.at(i) != '7' ||
         S.at(i) != '8' || S.at(i) != '9')) {
      judge = true;
      break;
    } else if (i == A && S.at(A) != '-') {
      judge = true;
    } else {
      continue;
    }
  }
  if (judge)
    cout << "No" << endl;
  else
    cout << "Yes" << endl;
}
