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