You planned a trip using trains and buses. The train fare will be A yen (the currency of Japan) if you buy ordinary tickets along the way, and B yen if you buy an unlimited ticket. Similarly, the bus fare will be C yen if you buy ordinary tickets along the way, and D yen if you buy an unlimited ticket.  Find the minimum total fare when the optimal choices are made for trains and buses.
ab=[int(i) for i in range(2)]
cd=[int(i) for i in range(2)]
print(min(ab)+min(cd))
ab=[int(input()) for i in range(2)]
cd=[int(input()) for i in range(2)]
print(min(ab)+min(cd))