#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  string S;
  cin >> A >> B;
  cin >> S;
  for (int i = 0; i < A; ++i) {
    if (!('0' <= S[i] && S[i] <= '9')) cout << "No";
    return 0;
  }
  if (!(S[A] == '-')) {
    cout << "No";
    return 0;
  }
  for (int i = A + 1; i < A + B + 1; ++i) {
    if (!('0' <= S[i] && S[i] <= '9')) cout << "No";
    return 0;
  }
  cout << "Yes";
  return 0;
}
