a = 24, b = -3
1) b < 7? да -> b := b+2 = -1; a := a-b = 24+1 = 25
2) b < 7? да -> b := b+2 = 1; a := a-b = 24-1 = 23
3) b < 7? да -> b := b+2 = 3; a := a-b = 23-3 = 20
4) b < 7? да -> b := b+2 = 5; a := a-b = 20-5 = 15
5) b < 7? да -> b := b+2 = 7; a := a-b = 15-7 = 8
6) b < 7? нет -> b = 7; a := 2*8 + 7 = 23
a = 23, b = 7