#include <fstream>
#include <string.h>
using namespace std;

ifstream cin("text.in");
ofstream cout("text.out");

int l, cnt;
char caractere[]=" ,.!?-+*/123456789=~@#$%^&*()_";

int main()
{
     char s[1005], *p;
     while(cin.get(s, 1005))
     {
            p=strtok(s, caractere);
            while(p!=NULL)
            {
                  l+=strlen(p);
                  cnt++;
                  p=strtok(NULL, caractere);
            }
     }
     cout << l/cnt;
}