#include <cstdio>
#include <string.h>
long long x,nr;
char *p,s[1048578],sep[]={"- ,.!;_?><12345678890"};
int main ()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    gets(s);
    p=strtok(s,sep);
    if(strlen(p)) x++,nr+=strlen(p);
    while (p)
    {
        p=strtok(NULL,sep);
        if(p==NULL) break;
        if(strlen(p)) x++,nr+=strlen(p);
    }
    printf("%lld",nr/x);
    return 0;
}