Ans will be 4 it should be y=y-1 instead of y+1
bresenham's algo is as below
1 Set X = 0 and Y = R
2. Set D = 3 – 2R
3. Repeat While (X < Y)
4. Call Draw Circle(Xc, Yc, X, Y)
5. Set X = X + 1
6. If (D < 0) Then
7. D = D + 4X + 6
8. Else
9. Set Y = Y – 1
10. D = D + 4(X – Y) + 10 [End of If]
11. Call Draw Circle(Xc, Yc, X, Y) [End of While]