[HaBo]

a = 1550
b = 1320
wanted = 2000

m = [[0 for y in range(b+1)] for x in range(a+1)]
solutionPath = None

def backtrack(myA, myB, path=[]):
    global solutionPath
    if m[myA][myB] == 0 or m[myA][myB] > len(path):
        m[myA][myB] = len(path)
    else:
        return
    if solutionPath != None and len(path) >= len(solutionPath):
        return
    if myA == wanted or myB == wanted or myA + myB == wanted:
        if solutionPath == None or len(solutionPath) > len(path):
            solutionPath = path
    if myA != a:
        backtrack(a, myB, path + [0]) # a fuellen
    if myB != b:
        backtrack(myA, b, path + [1]) # b fuellen
    if myA != 0 and myB != b:
        nextA = max(0, myA - b + myB)
        nextB = myB + myA - nextA
        backtrack(nextA, nextB, path + [2]) # a > b
    if myB != 0 and myA != a:
        nextB = max(0, myB - a + myA)
        nextA = myA + myB - nextB
        backtrack(nextA, nextB, path + [3]) # b > a
    if myA != 0:
        backtrack(0, myB, path + [4]) # a leeren
    if myB != 0:
        backtrack(myA, 0, path + [5]) # b leeren

backtrack(0, 0, [])
desc = ["fuelle(a)", "fuelle(b)", "a >> b", "b >> a", "leere(a)", "leere(b)"]
for i in solutionPath:
    print desc[i]
print "\nAnzahl Durchgaenge:", len(solutionPath)