#include <iostream>
#include <fstream>
using namespace std;
long long nrc,nr,i;
string s;
int main()
{
    ifstream f("text.in");
    ofstream g("text.out");
    while(f>>s)
        {
            nr++;
            for(i=0;i<s.size();i++)
            if(((s[i]>='a') and (s[i]<='z')) or ((s[i]>='A') and (s[i]<='Z')))
            {
                nrc++;
            }
            else if (s[i]==' ') nr++;
        }

    g<<nrc/nr;
    return 0;
}