#include<cstdio>
int main ()
{freopen ("text.in","r",stdin);
freopen ("text.out","w",stdout);
int c=0,l=0,i=0,n;
char a;
scanf("%c",&a);
while(a!=NULL&&i<=10000)
    {if((a<='z'&&a>='a')||(a<='Z'&&a>='A'))
        {c++;
        while((a<='z'&&a>='a')||(a<='Z'&&a>='A'))
            {
            l++;
            scanf("%c",&a);
            }
        }
    scanf("%c",&a);
    i++;
    }
printf("%d",l/c);
return 0;
}