#include <bits/stdc++.h>
using namespace std;
int A, B;
string S;
string solve() {
  int i = 0, j = 0;
  if ((S[A] == '-') && (1 <= A) && (B <= 5)) {
    for (i = 0; (i < A) && ('0' <= S[i]) && (S[i] <= '9'); i++)
      ;
    for (j = A + 2; (j < (A + B + 1)) && ('0' <= S[j]) && (S[j] <= '9'); j++)
      ;
  }
  return ((i + j) == (A + B)) ? "Yes" : "No";
}
int main() {
  cin >> A >> B >> S;
  cout << solve() << endl;
}
