}3.4-1`7
1(1)
1(2)
1(3)
1(4)
1(5)
1(6)E(7)
2(1)
2(2)
2(3)
3(1)
3(2)
3(3)
3(4)
4
5
6
7(1)
7(2)
7(3)
7(4)
7(5)