#include <iostream>
using namespace std;

int main() {
	int n;
	cin >> n;
	if( ( 0 <= n ) and ( n <= 9 ) ) cout << 1;
	else if( ( 10 <= n ) and ( n <= 99 ) ) cout << 2;
		else if( ( 100 <= n ) and ( n <= 999 ) ) cout << 3;
			else if( ( 1000 <= n ) and ( n <= 9999 ) ) cout << 4;
				else if( ( 10000 <= n ) and ( n <= 99999 ) ) cout << 5;
					else if( ( 100000 <= n ) and ( n <= 999999 ) ) cout << 6;
						else if( ( 1000000 <= n ) and ( n <= 9999999 ) ) cout << 7;
							else if( ( 10000000 <= n ) and ( n <= 99999999 ) ) cout << 8;
								else if( ( 100000000 <= n ) and ( n <= 999999999 ) ) cout << 9;
									else if( ( 1000000000 <= n ) and ( n <= 2000000000 ) ) cout << 10;
	return 0;
}