#include <iostream>
#include <cstdio>
#include <string.h>
#include <fstream>
using namespace std;
int main() 
{

    freopen("text.in","r+", stdin);
    freopen("text.out", "w", stdout);
	
	char S[501], *cuv;
	int nr_cuv=0;
	int suma_cif=0;

	gets(S);
		
	cuv=strtok(S," , . ( ) ~ ! @ # $ % ^ & * { } \ / : [ ] < > ? ! - =");
	while(cuv)
	{
		if(strlen(cuv)!=0)
		{
			nr_cuv++;
			suma_cif+=strlen(cuv);
		}
		cuv=strtok(NULL," , . ( ) ~ ! @ # $ % ^ & * { } \ / : [ ] < > ? ! - =");
	}
	cout<<suma_cif/nr_cuv;
return 0;
}