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