#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define s string
#define c char
#define co cout
#define ci cin
#define b bool
#define re return
ll n,ans;
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin>>n;
while(n>0){
ll x=n;
while(x>0){
ans++;
x/=10;
}
n/=2;
}
cout<<ans;
return 0;
}