#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int A, B;
  string S;
  bool can = false;
  cin >> A >> B >> S;
  if (S[A] == '-') {
    for (int i = 0; i < A; i++) {
      for (int j = 0; j <= 9; j++) {
        if (S[i] - '0' == j) can = true;
      }
    }
    for (int i = A; i < S.size(); i++) {
      if (!can) {
        can = false;
        continue;
      }
      for (int j = 0; j <= 9; j++) {
        if (S[i] - '0' == j) can = true;
      }
    }
  } else
    can = false;
  if (can)
    cout << "Yes\n";
  else
    cout << "No\n";
}
