#include <cstdio>
#include <cstring>
#define MAX 1005000
using namespace std;
int nr,tot;
char sir[MAX],*p,sep[]=",. !?'-;";
int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    gets(sir);
    p=strtok(sir,sep);
    while(p!=NULL)
    {
        nr++;
        tot+=strlen(p);
        p=strtok(NULL,sep);
    }
    printf("%d",tot/nr);
    return 0;
}