#include <iostream>
#include <fstream>
#define DM 1024*1100
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");

char C[DM];
int S,c,nr;

int main ()
{

    int i;

    fin.getline(C,DM);

    for(i=0;C[i];++i)
    {
        c=0;

        if((C[i]>='a' && C[i]<='z') || (C[i]>='A' && C[i]<='Z'))
        {
            while((C[i]>='a' && C[i]<='z') || (C[i]>='A' && C[i]<='Z')){    c++;    i++;    }
            nr++;
            S+=c;
            i--;
        }
    }

    fout<<S/nr;

    fin.close();
    fout.close();
    return 0;
}