#include <fstream>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
int main()
{
    char cuv[20];
    int u = 0, i, l = 0, c = 0, r;
    while( fin >> cuv )
    {
           u = 0;
           for( i = 0; i < strlen(cuv); ++i )
           {
                if( cuv[i] >= 65 && cuv[i] <= 90 )
                    l++;
                else
                    if( cuv[i] >= 97 && cuv[i] <= 122 )
                        l++;
                u = 1;
           }
           if(u)
                c++;
    } 
    r = l / c;
    fout << r << '\n';
    fin.close();
    fout.close();
    return 0;
}