g1: NC1CCCCC1
g2: NC1CCC(N)CC1
g3: CNC1CCC(N)CC1
g4: CNC1CCC(CC1)NC

The correct number of all MCS mappings should be

|MCS(g1, g1)| = 2
|MCS(g1, g2)| = 4
|MCS(g1, g3)| = 4
|MCS(g1, g4)| = 4

test cases for the combinations