def xor(a, b): return aand(nand(a, b), oor(a, b))
def xor(a, b): return aand(nand(a,b),oor(a,b))
def nnot(a): return nand(a,a)
def oor(a,b): return nand(nand(a,a),nand(b,b))
def nnot(a): return nand(a, a)
def aand(a, b): return nand(nand(a, b), nand(a, b))
def aand(a,b): return nand(nand(a,b),nand(a,b))