#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a;
	cin>>a;
	if(a<10) cout<<"1";
	else if(a<100) cout<<"2";
	else if(a<1000) cout<<"3";
	else cout<<"4";
	return 0;
}
/**************************************************************
	Problem: 1710
	User: admin
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/