A company has decided to use 0−1 integer programming to help make some investment decisions. There are three possible investment alternatives from which to choose, but if it is decided that a particular alternative is to be selected, the entire cost of that alternative will be incurred (i. e., it is impossible to build one-half of a factory). The 0-1 integer programming model is as follows:MAX Z = 5000 X1 + 7000 X2 + 9000 X3s. t. 25000 X1 + 32000 X2 + 29000 X3 ≤ 62000 (1)X1 + X2 + X3 ≤ 2 (2)-X1 + X2 ≤ 0 (3)16 X1 + 14 X2 + 19 X3 ≤ 36 (4)All X1, X2, X3 must be either 0 or 1where X1 = 1 if alternative 1 is selected, 0 otherwiseX2 = 1 if alternative 2 is selected, 0 otherwiseX3 = 1 if alternative 3 is selected, 0 otherwiseSuppose you wish to add a constraint that stipulates that both alternative 1 and alternative 3 must be selected. How would this constraint be written?The correct answer is: X1 + X3 = 2, so I want to know how