#include <fstream>
using namespace std;

int main()

{
ifstream in("text.in");
ofstream out("text.out");

char prop;
int cuv,lung,nrc;

    while(in>>noskipws>>prop)
    {
        if(isalpha(prop))
            cuv++;
        else
        {
            if(cuv!=0)
            {
                lung+=cuv;
                cuv=0;
                nrc++;
            }
        }
    }
    out<<lung/nrc;
    return 0;
}