#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int a, b;
  string str;
  cin >> a >> b;
  bool flag = true;
  cin >> str;
  for (int i = 0; i < str.length(); i++) {
    if (i != a) {
      if ((int)(str[i] - '0') < 10 && (int)(str[i] - '0' >= 0)) {
        flag = true;
      } else {
        flag = false;
      }
    }
  }
  if (str[a] == '-') {
  } else {
    flag = false;
  }
  if (str.length() > a + b + 1) {
    flag = false;
  }
  if (flag) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
