#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

int cal(ll x)
{
    int res = 0;
    while(x){
        res++;
        x/=10;
    }
    return res;
}

int main()
{
    ll n;
    while(scanf("%lld",&n)){
        int ans = 20;
        for(int i=1;1LL*i*i<=n;i++){
            if(n%i==0) ans = min(ans,cal(n/i));
        }
        printf("%d\n",ans);
    }
}
