#include <bits/stdc++.h>
using namespace std;
template <typename T>
T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
template <typename T>
T lcm(T a, T b) {
  return a * b / gcd(a, b);
}
template <typename T>
T finder(vector<T> vec, T number) {
  auto itr = find(vec.begin(), vec.end(), number);
  size_t index = distance(vec.begin(), itr);
  if (index != vec.size()) {
    return 1;
  } else {
    return 0;
  }
}
int main() {
  int A, B;
  cin >> A >> B;
  string S;
  cin >> S;
  bool ok = false;
  if (S[A] == '-') {
    for (int i = 0; i < A; i++) {
      if (0 <= S[i] - '0' <= 9) {
        for (int h = A + 1; h < A + B; h++) {
          if (0 <= S[h] - '0' <= 9) {
            ok = true;
          }
        }
      }
    }
  }
  if (ok)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
