//Uzun yol.
let total : number = 0
let userNumber : number = Number(prompt("Enter the number"))
for(let a :number = 1;a <= userNumber;a++) {
total += a
}
console.log(total)
//Kısa yol.
let number = Number(prompt("Enter the number"))
let total2 = number*(number+1)/2
console.log(total2)