#include <bits/stdc++.h>
using namespace std;
int A, B;
string S;
string solve() {
  int i;
  if ((S[A] == '-') && (1 <= A) && (B <= 5) && (sizeof(S) == (A + B + 1)))
    for (i = 0; (i < (A + B + 1)) && ('0' <= S[i]) && (S[i] <= '9'); i++)
      ;
  return (i == (A + B + 1)) ? "Yes" : "No";
}
int main() {
  cin >> A >> B >> S;
  cout << solve() << endl;
}
