function calc(n) { let maxLen = 0; let helper = function (index, len, sum) { if (sum === n) { if (len > maxLen) { maxLen = len } return } if (sum > n) return; for (let i = index; i < n; i++) { helper(i+1, len + 1, sum + i) } }; helper(1,0,0); return maxLen }