#include <stdio.h>

void overCiarovyKod(char *pole)
{
    int celksuma = 0;
    int k, j, i;


    for(i = 1; i < 13; i++)
    {
        j = i % 2;

        if(j = 0)

            celksuma = celksuma + pole[i] - 48;
        else

            if((pole[i]) * 2 <= 10)
                celksuma = celksuma + (pole[i]) * 2;
            else
                celksuma = celksuma + ((pole[i]) * 2) - 9;
    }

    k = celksuma % 10;

    if(k != pole[14])
    {
        printf("FAIL\n");
    }
    else
    {
        printf("OK\n");
    }

}


int main()
{
    char pole[] = "12391000105862";
    overCiarovyKod(pole);
    return 0;
}