# loop-de-loop.py

# loop-de-loop.py -- loop-de-loop-de-loop... bork-bork-bork!

def loop(v,i):
    if v:
        try:
            x,y,z = v[i]
        except:
            z = 1
            x,y = v[i]
        xx = x + z
        if (x > y and xx <= y) or (x < y and y <= xx):
            v.pop(i)
        else:
            v[i] = xx, y, z
0
loops = [(400,-50,-50),(0,100,20),(0,-500,-50),(25,0,-3),(0,10)]
while loops:
    print [z[0] for z in loops[:3]]
    for r in range(min(2,len(loops)-1),-1,-1):
        loop(loops,r)