#include<iostream.h>
#include<stdio.h>

unsigned long int litere,cuv;
char ch,val;


int main()
    {
    freopen("tir.in","r",stdin);freopen("tir.out","w",stdout);
    while(scanf("%c",&ch)!=EOF)
               {if((ch>='a' && ch<='z') || (ch>='A' && ch<='Z'))
                        {cuv++;
                         do {litere++;}
                                   while(scanf("%c",&ch)!=EOF && ((ch>='a' && ch<='z')||(ch>='A' && ch<='Z')));
                         }
                }
    printf("%lu",litere/cuv);
    fclose(stdin);fclose(stdout);
    return 0;
}