#include <bits/stdc++.h>
using namespace std;
long long p[11];
int main() {
  string s;
  cin >> s;
  int n = s.size();
  p[0] = 1;
  for (int i = 1; i < n; i++) p[i] = p[i - 1] * 9ll;
  long long ans = 1ll;
  for (char c : s) ans *= (long long)(c - '0');
  ans = max(ans, p[n - 1]);
  long long pre = 1;
  for (int i = 1; i <= n; i++) {
    for (long long j = 1; j < s[i - 1] - '0'; j++) {
      ans = max(ans, pre * j * p[n - i]);
    }
    pre *= (long long)(s[i - 1] - '0');
  }
  cout << ans << "\n";
  return 0;
}
