Galor Systems & Software Developments Fullstack Developer interview questions

There are 2 arrays of numbers, the size of the first array: n, the second: n+1. All the numbers of the first array (n) are included in the second array (n+1) The whole number appears once, What is the number that is in the second array (n+1) and not in the first array (n) Write an algorithm to find this number.