#include <iostream>
#include<fstream>
#include<string.h>
using namespace std;
fstream f("text.in",ios::in);
fstream g("text.out",ios::out);
 char a[20000000],*p;
 long long n,nr;
int main()
{
while(!f.eof())
{f>>a;
p=strtok(a," .,?;:'!@#$%^&*_+=-<>/*(){}");
if(!f.eof())
while(p)
{nr++;
n=n+strlen(p);
p=strtok(NULL," .,?;:'!@#$%^&*_+=-<>/*(){}");}}

g<<n/nr;
    return 0;
}