1 #include <bits/stdc++.h>
 2 #define ll long long int
 3 using namespace std;
 4 ll k[15]={1,4,27,256,3125,46656,823543,16777216,387420489,10000000000,
 5 285311670611,8916100448256,302875106592253,11112006825558016,437893890380859375};
 6 int main(){
 7   ll n;
 8   while(cin>>n){
 9     for(int i=14;i>=0;i--){
10       if(n>=k[i]){
11         cout<<i+1<<endl;
12         break;
13       }
14     }
15   }
16   return 0;
17 }