#include <fstream>

using namespace std;

ifstream f("text.in");
ofstream g("text.out");
string s;
long long litere = 0;
long long cuvinte = 0;

int main()
{
    while(f>>s)
    {
        int ok = 0;
        for(int i = 0; i<s.size(); i++)
        {
            if((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z'))
            {
                if(ok == 0)
                {
                    ok = 1;
                    cuvinte++;
                }

                litere++;
            }
            else if(ok == 1)
            {
                ok = 0;
            }
        }
    }
    g<<litere/cuvinte;
    return 0;
}