#include <fstream>
#include <cstring>

using namespace std;

ifstream fin ("teren.in");
ofstream fout("teren.out");

int litere, cuvinte;
char cuvant[1200005];

int main()
{
    while(fin >> cuvant)
    {
        bool cuvantNou = true;
        int limita = strlen(cuvant);
        for(int i = 0; i < limita; i++)
        {
            if((cuvant[i] >= 'a' && cuvant[i] <= 'z') || (cuvant[i] >= 'A' && cuvant[i] <= 'Z'))
            {
                if(cuvantNou)
                {
                    cuvantNou = false;
                    cuvinte++;
                }
                litere++;
            }
            else
                cuvantNou = true;
        }
    }
    if(cuvinte == 0)
        fout << 0;
    else
        fout << litere / cuvinte;
}