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
N = [int(input()) for i in range(4)]

a = min(N[0],N[1])
b = min(N[2],N[3])

print(a+b)