Giving N integers, V1, V2,,,,Vn, you should find the biggest value of F.
Each test case contains a single integer N (1<=N<=100). The next line contains N integers, meaning the value of V1, V2....Vn.(1<= Vi <=10^8).The input is terminated by a set starting with N = 0. This set should not be processed.
For each test case, output the biggest value of F you can find on a line.