Let \(a_1, a_2, a_3, a_4\) be an A.P. of four terms such that each term of the A.P. and its common difference \(l\) are …

Let \(a_1, a_2, a_3, a_4\) be an A.P. of four terms such that each term of the A.P. and its common difference \(l\) are integers. If \(a_1+a_2+a_3+ a_4=48\) and \(a_1 a_2 a_3 a_4+l^4=361\), then the largest term of the A.P. is equal to