using namespace std;
#include<fstream>
#include<string.h>


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

char s[100000000],cuv[100000000];


int main()
{

    unsigned long long int nrcuv=0,nrlit=0;
    int k=0,i,x;
    char *p,sep[]=" ",*q;
    f.get(s,100000001);

    p=strtok(s,sep);

    while (p)
    {
        strcpy(cuv,p);
        x=strlen(cuv);
        for(i=0; i<x; i++)
        {
            if((cuv[i]>='a' && cuv[i]<='z') || (cuv[i]>='A' && cuv[i]<='Z'))
            {
                nrlit++;
                if(k==0)
                {
                    nrcuv++;
                    k=-1;

                }

            }
            else k=0;


        }
        k=0;

        p=strtok(NULL,sep);
    }

    g<<nrlit/nrcuv;





    return 0;
}