*** File 1 (2 lines) and File 2 (3 lines):
file 1 line 1	file 2 line 1
file 1 line 2	file 2 line 2
	file 2 line 3
*** File 2 (3 lines) and File 1 (2 lines):
file 2 line 1	file 1 line 1
file 2 line 2	file 1 line 2
file 2 line 3	
*** File 1 (2 lines) and File 3 (2 lines):
file 1 line 1	file 3 line 1
file 1 line 2	file 3 line 2