#include <fstream>

using namespace std;
int nr,l,m;
long long s;
char a[1000002];
ifstream f("text.in");
ofstream g("text.out");
int main()
{
    while(f.get(a[++nr]))
    {
        if((a[nr]>='A' && a[nr]<='Z') || (a[nr]>='a' && a[nr]<='z'))l++;
        else
        {
            if((a[nr-1]>='A' && a[nr-1]<='Z') || (a[nr-1]>='a' && a[nr-1]<='z'))
            {
                m++;
                s=s+l;
                l=0;
            }
        }
    }
    g<<s/m<<'\n';
    return 0;
}