#include<cstdio>
using namespace std;
int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    int s=0,nr=0,nr1=0;
    char x1;
    while(scanf("%c",&x1)!=EOF)
    {
        if(x1>='a'&&x1<='z') nr++;
            else
            {
                if(nr!=0) {s=s+nr;nr1++;}
                nr=0;
            }
    }
    printf("%d",s/nr1);
    return 0;
}