Problem:
Score : 200 points

Problem Statement

A group of people played a game. All players had distinct scores, which are positive integers.

Takahashi knows N facts on the players' scores. The i-th fact is as follows: the A_i-th highest score among the players is B_i.

Find the maximum possible number of players in the game.

Constraints

1 \leq N \leq 10^5

1 \leq A_i \leq 10^9(1\leq i\leq N)

0 \leq B_i \leq 10^9(1\leq i\leq N)

If i ≠ j, A_i ≠ A_j.

There exists a possible outcome of the game that are consistent with the facts.

All input values are integers.

Inputs

Input is given from Standard Input in the following format:

N
A_1 B_1
:
A_N B_N

Outputs

Print the maximum possible number of players in the game.

Sample Input 1

3
4 7
2 9
6 2

Sample Output 1

8

The maximum possible number of players is achieved when, for example, the players have the following scores: 12,9,8,7,5,2,1,0.

Sample Input 2

5
1 10
3 6
5 2
4 4
2 8

Sample Output 2

7

Sample Input 3

2
1 1000000000
1000000000 1

Sample Output 3

1000000001

Solution in JavaScript (node.js v5.12) (judge verdict: Runtime Error)

'use strict'
 
function Main(input) {
    var line = input.split('\n');
    line = line.pop();
    line = line.shift();
    let low = 0;
    let min = 0;
    for (let i = 1; i < line.length; i++) {
        const arg = line[i].split(' ');
        if (arg[0] > lowest) {
            low = parseInt( arg[0] , 10);
            min = parseInt( arg[1] , 10);
        }
    }
    console.log(low + min);
}
 
Main(require("fs").readFileSync("/dev/stdin", "utf8"));