#include <stdio.h>
#include <string.h>
#include <stdlib.h>

char s[1024*1024+5],t,*p,sep[]=" ,.-?!;:'({)}";

int i,nr,l;

int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);

    gets(s);

    p=strtok(s,sep);

    while(p!=0){
        l+=strlen(p);
        nr++;
        p=strtok(NULL,sep);
    }
    printf("%d",l/nr);

    return 0;
}