Tester if-switch java

I have a school project due next week and I'm trying to crack the way to solve this question. The problem was to develop a program that test my previous one, which had to print the 2 smallest numbers out of 4 using if-switch. What I need to test:

if (a>b) {

    int tmp = b;
    b = a;
    a = tmp;
}

if (b>c) {
    int tmp = c;
    c = b;
    b = tmp;
}

if (a>d) {
    int tmp = d;
    d = a;
    a = tmp;
}

if (b>d) {
    int tmp = d;
    d = b;
    b = tmp;
}

My limitations are:

• Must only use: int, for,while, if, scanner (so no break or arrays/Boolean/etc)
• No user input, must enter to test a,d=0 c,b=1.
• I know there are 16 options, if all are true, then print verified, in any case there must be written in the tester a code that prints 1 example if false

I'm trying to solve this with for statements, however I only got as far as just printing 1+2,3+4... in: for (int i=0; i<=16 ; i++).

1. How do I check the numbers they want (0,1) over and over in for loop?
2. I would appreciate a hint on printing just 1 example for the false print