Question

Akhil is very good at string manipulation.One day a professor gave him a challenge to solve. The challenge is very simple.Find the number of strings of length N where each string must contain only first four alphabets of english literature. To make the question harder he also give M strings. These M strings should not be present as substrings. Note : Since some times the ans is large perform modulo 1000000007. Input Format The first line contains T which has number of test cases The first line of each test case contains 2 space-separated integers N and M The next M lines contains a string S, which should not be present

Answer 1

Answer:

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