def print_shopping_list(dish1, dish2):
    ingrids1 = set(dish1.keys())
    ingrids2 = set(dish2.keys())
    ingrids = ingrids1.union(ingrids2)

    for i in ingrids:
        amount = 0
        if i in dish1.keys():
            amount += dish1[i]
        if i in dish2.keys():
            amount += dish2[i]

        print(i + ':', amount)