#include <fstream>
#include <string.h>

using namespace std;

ifstream f("text.in");
ofstream g("text.out");
char lc,ul;
int nrcuv=0,nrlitere=0;
int litera (char c)
{
    if((c>='a' && c<='z') || (c>='A' && c<='z'))
        return 1;
    return 0;
}
int main()
{
    while(f.get(lc)) {
        if(litera(lc)==1)
            nrlitere++;
        else
            if(litera(lc)==0 && litera(ul)==1)
                nrcuv++;
        ul=lc;
    }
    g<<nrlitere/nrcuv;
    return 0;
}