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

char s[10000000];

int tc,nrcuv;

int main()
{
    int i;
    in.getline(s,10000000);
    while(s[0]!=NULL)
    {
        for(i=0;s[i]!=NULL;i++)
        {
            if(isalpha(s[i]))
            {
                nrcuv++;
                while(isalpha(s[i]))
                    {
                        tc++;
                        i++;
                    }
            }
        }
        s[0]=NULL;
        in.getline(s,8400000);
    }
    if(nrcuv==0)
        out<<0;
    else
        out<<tc/nrcuv;
    return 0;
}