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

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