SOLVE
LATER
Xsquare loves to play with the strings very much. This time, he has two strings named as S_{1} and S_{2} along with the M pairs of integers where i^{th} pair of integers is denoted by L_{i} , R_{i}. Each of the two strings S_{1} and S_{2} consists of N lower case letters.
In one move, Xsquare can select one pair of integers out of the available M pairs of integers. Let the chosen pair of integers is x^{th} one. So accordingly Xsquare can modify the string S_{1} by swapping its L_{x}^{th} and R_{x}^{th} characters .
Xsquare can apply the above move as many times as he wants on the string S_{1} in order to maximise the length of Fantastic Sequence between the string S_{1} and S_{2}.
Definition
Here A Fantastic Sequence of length K between the two strings S_{1} and S_{2} is defined as the sequence of K integers say
Xsquare knows that finding the solution of this problem will definately take too much time which offcourse Xsquare does not have as he is the most busy person in this world. So he asked you to help him in accomplishing this task.
First line of input contains a single integer T denoting the number of test cases. Each test case consists of several lines. First line of each test case contains two space separated integers N and M denoting the length of each string and number of pairs respectively. Next two lines of each test case contains two strings denoting string S_{1} and string S_{2} respectively. Next M lines of each test case contains a pair of integers where i^{th} pair of integers is present in the i^{th} line.
For each test case, print two lines.
1 ≤ T ≤ 10^{5}
1 ≤ N ≤ 10^{5}
1 ≤ M ≤ 10^{5}
1 ≤ L_{i},R_{i} ≤ N
Sum of N and M over all the test cases will not exceed 5*10^{5} .
All the test data is strictly according to constraints.
Test 1 :
1. Maximum possible length of the fantastic sequence is 1.
2. There are two possible modified strings S1 "st" and "ts" such that length of the fantastic sequence is 1 but we always have to choose the lexographically smallest one. Therefore the answer is "st" .
Test 2 :
1. Maximum possible length of the fantastic sequence is 1.
2. There are two possible modified strings S1 "sa" and "as" such that length of the fantastic sequence is 1 but we always have to choose the lexographically smallest one. Therefore the answer is "as" .