#include <fstream>
#include <cstring>
using namespace std;

#define NMax 1100000

ifstream f("text.in");
ofstream g("text.out");

char sir[NMax];
char c;
int n;
bool last,ok;
int nrcuv, litere;

int main()
{
    int i;

    while(f>>sir)
    {
        n = strlen(sir);
        last = false;
        for(i=0;i<n;++i)
        {
            c = sir[i];
            if( (c>='a' && c<='z') || (c>='A' && c<='Z') )
            {
                ok = true;
                last = true;
                ++litere;
            }
            else if(last == true)
            {
                last = false;
                ++nrcuv;
            }
        }
        if(ok == true) ++nrcuv;
    }

    g<<litere / nrcuv<<"\n";

    f.close();
    g.close();
    return 0;
}