#include <iostream>
#include<fstream>
#include<string.h>
using namespace std;

int main()
{
    long i,nrcuv=0,nrl=0,n;
   char v[1000],simbol[]=" -,.!?",litere[]="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    ifstream f("text.in");
    ofstream g("text.out");
    f.get(v,1000);
     n=strlen(v);
    for(i=0;i<n;i++)
        if(strchr(litere,v[i])&&strchr(litere,v[i+1]))
                    nrl++;
        else
                        if(strchr(litere,v[i])&&strchr(simbol,v[i+1]))
                            {
                                nrcuv++;
                                nrl++;
                            }
    if(strchr(litere,v[n-1]))
         nrcuv++;
    g<<nrl/nrcuv;

    return 0;
}