Alaska14

let d12 = [6, 62, 60, 70, 1, 5];

function f12() {
    let out = '';
    let input = +document.querySelector('.i-12').value;
    for (i = 0; i < d12.length; i++) {
        if (d12[i] === input) {
            out = [i];
            break
        } else {
            out = -1;
        }
    }

    document.querySelector('.out-12').innerHTML = out;
}

document.querySelector('.b-12').onclick = f12;