import copy

def partition(N,ar,index,current):
    if N<0:
        return 0
        #dead end
    elif N==0:
        ans.append(current)
    else:
        if index>= len(ar):
            return 0
            #do nothing
        else:
            if ar[index]<=N:
                aa=copy.deepcopy(current)
                aa.append(ar[index])
                partition(N-ar[index],ar,index,aa)
            bb=copy.deepcopy(current)
            partition(N,ar,index+1,bb)


#program
ans=[[]]
ar=[1,2,3,4,5,6,7]
partition(4,ar,0,list())
print(ans)