#include<stdio.h>
#define ll long long
int main()
{
	ll n;
	ll x;
	int ans = 0;
	scanf("%lld",&n);
	for(ll i = 1; i * i <= n; i++)
	{
		if(!(n % i))  x = n / i;
	}
	while(x > 0)
	{
		ans ++;
		x /= 10;
	}
	printf("%d\n",ans);
	return 0;
}