#include <stdio.h>

int main()
{
    int s=0,m=0,j=0,y=1;
    char c=' ',c1=' ';
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    while (c!=EOF)
    {
        c1=c;
        if (scanf("%c",&c)) y=0;
        else y=1;
        if (y==1) break;
        if ((int)c>64 && (int)c<123) ++s;
        else if ((int)c1>64 && (int)c1<123)
        {
            ++m;
            j+=s;
            s=0;
        }
    }
    printf("%d",j/m);
    return 0;
}