#include <cstdio>
#include <cstring>
using namespace std;

char s [256] ,  *p  , sep[7] = " ,;!?-" , a [50][50];
int n , i , suma;

int main()
{
    freopen ("text.in" , "r" , stdin);
    freopen ("text.out" , "w" , stdout);
    gets (s);
    p = strtok (s , sep);

    while(p != NULL)
    {
        strcpy (a[++n] , p);
        p = strtok(NULL , sep);
    }

    for(i =  1 ; i <= n ; ++i)
        suma += strlen (a[i]);

    printf ("%d" , suma/n);

    return 0;
}