#include<cstdio>
#include<cstring>
char str[100000],*pch;
long long size,k;
int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    gets(str);
    pch = strtok (str," ,.-!?");
    while (pch != NULL)
    {
        size+=strlen(pch);
        k++;
        pch = strtok (NULL, " ,.-!?");
    }
    printf("%d\n",size/k);
    return 0;
}