#include<fstream>
#include<iostream>
using namespace std;
ifstream in("text.in");
ofstream out("text.out");
int main()
{
    char a,b='\0';
    unsigned long long int cuv=0,nr=0;
    while(in.get(a))
    {
        if((a<='Z' and a>='A' ) or (a>='a' and a<='z'))
            nr++;
        else
            if((b<='Z' and b>='A' ) or (b>='a' and b<='z'))
               cuv++;
        b=a;
    }
    out<<nr/cuv;
}