#include <bits/stdc++.h>
using namespace std;
long long n, i, j, a, b, c, k;
int main() {
  cin >> n;
  a = sqrt(n);
  for (i = 1; i < a; i++)
    if (n % i == 0) j = n / i;
  for (; j != 0; j /= 10) c++;
  cout << c;
}
