In computing, diff is a file comparison utility that outputs the differences between two files. It is typically used to show the changes between a file and a former version of the same file. Diff displays the changes made per line for text files. The operation of diff is based on solving the longest common subsequence problem which is as follows: Given two sequences A=a1 ,a​2 ,⋯,a​M , and B=b1 ,b2 ,⋯,bN​​ , find the length, k, of the longest sequence C=c1 ,c​2 ,⋯,ck such that C is a subsequence of both A and B. As an example, if A = d, y, n, a, m, i, c and B = p, r, o, g, r, a, m, m, i, n, g then the longest common subsequence is a, m, i and has length 3. From the longest common subsequence it's only a small step to get diff-like output: dyn-progr+m+c-ng+ where - means a deletion from and + means an addition to the first string. Now you are supposed to simulate the diff operation.

Each input file contains one test case. Each case contains the contents of two files. The case starts with two non-negative integers N and M (both ≤50), then followed by N+M lines, each contains a string of no more than 80 characters. The first N lines are the contents of the first file, while the second M lines are of the second file.

For each test case, if there is no difference found between the two files, print in a line

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