#include<cstdio>
#include<cstring>
char c;
int lit,sum,word;
int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    while(scanf("%c",&c)>0)
    {
        if((c>='A'&&c<='Z')||(c>='a'&&c<='z'))
            lit++;
        else
            if(lit)
                sum+=lit,word++,lit=0;
    }
    printf("%d\n",sum/word);
    return 0;
}