#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1.0);
int main() {
  int A, B;
  char s[333];
  cin >> A >> B >> s;
  int yes = 1;
  for (int i = 0; i < A + B + 1; i++) {
    if (i != A && '0' <= s[i] && s[i] <= '9')
      yes = 1;
    else if (i == A && s[i] == '-')
      yes = 1;
    else
      yes = 0;
  }
  if (yes)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
