Input:
block1
|block2
block3
block4
output:
block1|block2
block3
block4
Input:
block1
block2
|block3
block4
output:
block1
block2|block3
block4
Input:
block1
block2
block3
block4
block5
|block6
block7
output:
block1
block2
block3
block4
block5|block6
block7