#include <fstream>
#include <string.h>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");

char text[1050000];
int lCuv, sumaCuv, nrCuv, medieCuv, i;

int main()
{
    while(f.get(text[++i])){
        if((text[i] >= 'a' && text[i] <= 'z') || (text[i] >= 'A' && text[i] <= 'Z')){
            lCuv ++;
        }else{
            if(lCuv){
                nrCuv ++;
                sumaCuv += lCuv;
                lCuv = 0;
            }
        }
    }

    medieCuv = sumaCuv / nrCuv;

    g<<medieCuv<<'\n';

    return 0;
}