How to remove all the rows if first two columns has same number?

I have matrix like this. I wants to remove the all the rows which contain same numbers in first two columns

1 1 1 200 2

1 2 2 200 2

1 3 3 200 2

1 4 4 200 2

2 1 1 200 2

2 2 2 200 2

2 3 3 200 2

2 4 4 200 2

3 1 1 200 2

3 2 2 200 2

3 3 3 200 2

3 4 4 200 2

4 1 1 200 2

4 2 2 200 2

4 3 3 200 2

4 4 4 200 2

for example

1 2 2 200 2

1 3 3 200 2

1 4 4 200 2

2 1 1 200 2

2 3 3 200 2

2 4 4 200 2

3 1 1 200 2

3 2 2 200 2

3 4 4 200 2

4 1 1 200 2

4 2 2 200 2

4 3 3 200 2

Answer 1

[Guillaume]

Two of many possible ways:

yourmatrix(diff(yourmatrix(:, [1 2]), [], 2) == 0 , :) = [];

yourmatrix(yourmatrix(:, 1) == yourmatrix(:, 2), :) = [];