#include <string>
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
    int nrlit=0,nrcuv=0;
    char c,c1;
    bool k;
    FILE *f=fopen("text.in","r");
    while(fscanf(f,"%c",&c)==1)
    {
        if((c>='a'&&c<='z')||(c>='A'&&c<='Z')){
        nrlit++;k=0;}
        else if(k==0){
        nrcuv++;k=1;}
    }
    if(k==1)nrcuv++;
    ofstream("text.out")<<(nrlit)/nrcuv;
    return 0;
}