a[0] = 0
a[1] = 0
a[2] = 0
a[3] = 0
a[4] = 0

a[0] = 5
a[1] = 6
a[2] = 7
a[3] = 0
a[4] = 0

a[0] = 0
a[1] = 0
a[2] = 0
a[3] = 0
a[4] = 0

a[0] = 0
a[1] = 5
a[2] = 6
a[3] = 7
a[4] = 0