selection of rows in a matrix

how to select only few rows in a matrix

36 13

9 21

23 32

35 5

3 43

in ths five elements i have select only 3 rows which is

36 13

23 32

3 43

which is row 1, row 3, row 5

Answer 1

[Alex Mcaulley]

A = [36    13
     9    21
    23    32
    35     5
     3    43]
B = A([1,3,5],:)