#include <stdio.h>

#define BOD_X(s) body[s][0]
#define BOD_Y(s) body[s][1]
#define BOD_XY(s) ((((long)(BOD_X(s)))<<sizeof(int))+BOD_Y(s))

int main(int argc, char *argv[])
{
    int i, body[3][2], maxX, minX, midX;

    for(i=0;i<3;i++)
    {
        printf("Zadejte souradnice bodu %c:\n", 'A' + (char)i);
        if (scanf("%d %d", &(BOD_X(i)),&(BOD_Y(i)))==2)
            continue;

        printf("Nespravny vstup.\n");
        return 1;
    }

    maxX=BOD_XY(0)<BOD_XY(1);
    minX=(!maxX);

    if (BOD_XY(maxX)<BOD_XY(2))      maxX=2;
    else if (BOD_XY(minX)>BOD_XY(2)) minX=2;

    midX=(~(maxX | minX) & 3);

    if (((BOD_X(1)-BOD_X(0))*(BOD_Y(2)-BOD_Y(0))) != ((BOD_X(2)-BOD_X(0))*(BOD_Y(1)-BOD_Y(0))))
            printf("Body nelezi na jedne primce.\n");
    else if ((BOD_XY(minX)==BOD_XY(midX)) || (BOD_XY(maxX)==BOD_XY(midX)) )
            printf("Body lezi na jedne primce.\nNektere body splyvaji - zadny neni uprostred.\n");
        else
            printf("Body lezi na jedne primce.\nProstredni je bod %c.\n", 'A' + (char)midX);

    return 0;
}