function backToThePast (input){
    let heritage = Number(input.shift());
    let lastYear = Number(input.shift());
    let age = 18;



    for ( i = 1800 ; i <= lastYear ; i++){
        if ( i % 2 == 0){
           heritage -= 12000;
           age ++;
        }else {
            heritage -= 12000 + (50 *age);
            age ++;
        }

    }
if (heritage >= 0){
console.log(`Yes! He will live a carefree life and will have ${heritage.toFixed(2)} dollars left.`)
}else{
    console.log(`He will need ${Math.abs(heritage.toFixed(2))} dollars to survive.`)
}

}