aa

#include <stdio.h>
#include <string.h>

#define ll long long

int getValueLen(const ll a);
int getMax(const int a, const int b);

int main(){
    /*入力*/
    ll n;
    scanf("%lld",&n);
    /*初期設定*/
    ll finalAns;
    finalAns = getValueLen(n);
    /*約数A及びBの探索*/
    for(ll a=1; a*a<=n;a++){
        if(n % a != 0)  continue;
        const ll b = n / a;
        const int cmpResult = getMax(getValueLen(a), getValueLen(b));
        if(finalAns > cmpResult)    finalAns = cmpResult;
    }
    printf("%lld",finalAns);
    return 0;
}
int getValueLen(const ll a){ /*Needn'tFix*/
    char setStrA[a];
    /*aの桁数の取得*/
    sprintf(setStrA, "%lld", a);
    int lengthA = strlen(setStrA);

    return lengthA;
}
int getMax(const int a, const int b){ /*Needn'tFix*/
    if(a > b)   return a;
    else        return b;
}