//#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;

ifstream in("text.in");
ofstream out("text.out");

int main()
{
    int nrc=0,l=0;
    char c;
    while(!in.eof())
    {
        in>>c;
        if(isalpha(c))
        {
            while(isalpha(c))
                ++l;
            ++nrc;
        }
    }
    out<<l/nrc;

    return 0;
}