on the bottom of the ocean

function main(lines) {
    lines=lines.map(Number);
    let island=function(x,y) {
        switch(true){
            case (x>=5&&x<=7&&y>=3&&y<=6):
                console.log('Samoa');
                break;
            case (x>=8&&x<=9&&y>=0&&y<=1):
                console.log('Tokelau');
                break;
            case (x>=1&&x<=3&&y>=1&&y<=3):
                console.log('Tuvalu');
                break;
            case (x>=0&&x<=2&&y>=6&&y<=8):
                console.log('Tonga');
                break;
            case (x>=4&&x<=9&&y>=7&&y<=8):
                console.log('Cook');
                break;
            default:
                console.log('On the bottom of the ocean');
                break;
        }
    };
    for (let i = 0; i < lines.length; i+=2) {
        let x=lines[i];
        let y=lines[i+1];
        island(x,y);
    }
}

main(['4', '2', '1.5', '6.5', '1', '3']);
// main(['6','4']);