#include <fstream>

using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
const char WHITE_SPACE(32);
int main()
{
    char ch;
    int cnt=0,ok=0,lit=0;
    while(fin>>ch)
    {

              // fout<<"spatiu "<<ok<<endl;
        if(ch>='a' && ch<='z' || ch>='A' && ch<='Z')
        {
            ok++;
            lit++;

        }
        else
        {

            if(ok>0)
                {cnt++;


                }
            ok=0;
        }
        if (fin.peek() == WHITE_SPACE  )
        {
             if(ok>0)
                {cnt++;


                }
            ok=0;
        }
    }
    if(cnt!=0)
        fout<<lit/cnt;
    else
        fout<<0;
    return 0;
}