#include <iostream>
#include<fstream>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
int nr,nr1;
char c;
int main()
{int nr=0,nr1=0;
char c;
fin>>c;
while(fin.get(c))
{if((c>='A'&&c<='Z')||(c>='a'&&c<='a'))
 {nr++;
     while(fin.get(c) && c != '\n' && (c >= 'A' && c<='Z') || (c >= 'a' && c <= 'z'))
            nr++;
           nr1++;}}
    fout<<nr/nr1;
    return 0;
}