function solution(a, b) {
if (a === b) return a;
let sum = 0;
let bigger = a > b ? a : b;
let smaller = a > b ? b : a;
for (let i=smaller; i<=bigger; i++) {
sum += i;
}
return sum;
}
function adder(a, b, s = 0){
for (var i = Math.min(a, b); i <= Math.max(a, b); i++) s += i;
return s;
}
function adder(a, b){
var result = 0
return (a+b) * (Math.abs(a-b)+1) / 2;
}