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Score : $100$ points

### 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