/**

  • @param costs Array {Number[][]}
  • @return Number

*/

var Solution = function(costs) {

costs.sort((o1, o2) => {
    return o1[0]-o1[1]-(o2[0]-o2[1]);
});
// console.log(costs);
let sum = 0;
let middle = Math.floor(costs.length/2);
for(let i = 0; i < middle; i++){
    sum += costs[i][0];
}
for(let i = middle; i < costs.length; i++){
    sum += costs[i][1];
}
return sum;

};