#include <bits/stdc++.h>
using namespace std;
string str1;
bool flag = false;
int main(int argc, char const *argv[]) {
  int a, b;
  cin >> a >> b;
  cin >> str1;
  int len = str1.length();
  for (int i = 0; i < a; i++) {
    if (!isdigit(str1[i])) {
      goto fin;
    }
  }
  for (int i = a; i < len; i++) {
    if (str1[a] == '-') {
      flag = true;
    }
  }
fin:
  if (flag == true)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
