#include <fstream>

using namespace std;

char x;
int nrcuv, nrlit, unrlit;

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

int isLetter(char x)
{
    if(x>='a' && x<='z' || x>='A' && x<='Z')
        return 1;
    return 0;
}

int main()
{
    while(!f.eof())
    {
        x=f.get();
        if(isLetter(x))
        {
            nrlit++;
        }
        else
        {
            if(unrlit != nrlit)
            {
                nrcuv++;
                unrlit=nrlit;
            }
        }
    }
    if(unrlit != nrlit)
    {
        nrcuv++;
        unrlit=nrlit;
    }
    g<<nrlit/nrcuv;

    return 0;
}