B'Toad Zitz has an array of integers, each integer is between 0 and m-1 inclusive. The integers are a_1, a_2, ldots, a_n . In one operation Zitz can choose an integer k and k indices i_1, i_2, ldots, i_k such that 1 <= q i_1 < i_2 < ldots < i_k <= q n . He should then change a_{i_j} to ((a_{i_j}+1) bmod m) for each chosen integer i_j . The integer m is fixed for all operations and indices. Here x bmod y denotes the remainder of the division of x by y . Zitz wants to make his array non-decreasing with the minimum number of such operations. Find this minimum number of operations. The first line contains two integers n and m ( 1 <= q n, m <= q 300 ,000 ) -- the number of integers in the array and the parameter m . The next line contains n space-separated integers a_1, a_2, ldots, a_n ( 0 <= q a_i < m ) -- the given array. Output one integer: the minimum number of described operations Zitz needs to make his array non-decreasing. If no operations required, print 0 . It is easy to see that with enough operations Zitz can always make his array non-decreasing. In the first example, the array is already non-decreasing, so the answer is 0 . In the second example, you can choose k=2 , i_1 = 2 , i_2 = 5 , the array becomes [0,0,1,3,3] . It is non-decreasing, so the answer is 1 . '...