Problem Statement

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.

Sample Input 1

600
300
220
420

Sample Output 1

520

The train fare will be $600$ yen if you buy ordinary tickets, and $300$ yen if you buy an unlimited ticket. Thus, the optimal choice for trains is to buy an unlimited ticket for $300$ yen. On the other hand, the optimal choice for buses is to buy ordinary tickets for $220$ yen.

Therefore, the minimum total fare is $300 + 220 = 520$ yen.

Sample Input 2

555
555
400
200

Sample Output 2

755

Sample Input 3

549
817
715
603

Sample Output 3

1152