众所周知，$\lfloor\lg n\rfloor=d-1$，其中 $d$ 是 $n$ 的数字位数。

#include <bits/stdc++.h>
using namespace std;
int main()
{
	freopen("log.in", "r", stdin);
	freopen("log.out", "w", stdout);
	int cnt = 0;
	char c = getchar();
	while(c != EOF) cnt++, c = getchar();
	printf("%d", cnt - 1);
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main(){
    freopen("log.in","r",stdin);
    freopen("log.out","w",stdout);
    char a=getchar();
    int ans=-1;
    while(a!=EOF){
        ans++;
        a=getchar();
    }
    cout<<ans;
    fclose(stdin);
    fclose(stdout);
    return 0;
}