#include<string.h>
#include<stdio.h>
#define MAX 1500000

using namespace std;

int i, l, n;
char c, s[MAX];

int main ()
{
    FILE *fis = fopen ("text.in", "r");
    fgets(s, MAX, fis);
    while ( !feof(fis) )
    {
    s[strlen(s)-1] = NULL;
    char *p;
    p = strtok (s, " ,.?!-");
    while ( p != NULL )
    {
        n ++;
        l += strlen(p);
        p = strtok(NULL, " ,.?!-");
    }
    fgets(s, MAX, fis);
    }
    fclose(fis);
    FILE *fis2 = fopen ("text.out", "w");
    fprintf (fis2, "%d\n", l/n);
    fclose(fis2);
    return 0;
}