#include <fstream>
using namespace std;
ifstream fi("text.in");
ofstream fo("text.out");
int Nr_char,Nr_Cuv;
char c;
bool cuv_bun;
int main()
{
    while(!fi.eof())
    {
        fi.get(c);
        if((c>='A' && c<='Z') || (c>='a' && c<='z'))
        {
            Nr_char++;
            cuv_bun=true;
        }
        else
            if(cuv_bun==true)
            {
                Nr_Cuv++;
                cuv_bun=false;
            }
    }
    fo<<Nr_char/Nr_Cuv;
    fi.close();
    fo.close();
    return 0;
}