Sum of Two Numbers - Nested Loops

function sumOfTwoNumbers(input) {

    let startNum = Number(input[0]);
    let endNum = Number(input[1]);
    let sum = Number(input[2]);

    let isFound = false;
    let combination = 0;
    let numberOne = 0;
    let numberTwo = 0;
    for (let first = startNum; first <= endNum; first++) {
        for (let second = startNum; second <= endNum; second++) {
            combination++;
            if (first + second === sum) {
                numberOne = first;
                numberTwo = second;
                isFound = true;
                break;
            }
        }
        if (isFound) {
            break;
        }
    }
    if (isFound) {
        console.log(`Combination N:${combination} (${numberOne} + ${numberTwo} = ${sum})`);
    } else {
        console.log(`${combination} combinations - neither equals ${sum}`);
    }

}

sumOfTwoNumbers(["1", "10", "5"])