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.

Constraints

* 1 \leq A \leq 1 000
* 1 \leq B \leq 1 000
* 1 \leq C \leq 1 000
* 1 \leq D \leq 1 000
* All input values are integers.

Input

Input is given from Standard Input in the following format:


A
B
C
D


Output

Print the minimum total fare.

Examples

Input

600
300
220
420


Output

520


Input

555
555
400
200


Output

755


Input

549
817
715
603


Output

1152
a, b, x, y = [int(input()) for _ in range(4)]
print(min(a, b) + min(x, y))