#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e9 + 7;
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
int main() {
  int A, B;
  string S;
  cin >> A >> B >> S;
  int p = S.find('-') + 1;
  int o = S.find('-', A + 2);
  if (p != A + 1 && o == -1)
    cout << "No" << endl;
  else
    cout << "Yes" << endl;
  return 0;
}
