We define a recursive function f(n) which takes a positive integer n as input and does the following:
if n < 10
else return f( sum_of_digits(n) )
where sum_of_digits(n) returns the sum of the digits of the positive integer n.Given two positive integers A and B, the task is to find the value of f(AB).
The first line of input contains a single integer T denoting the number of test cases. Then T test cases follow. Each test case consists of exactly one line. This line consists of two space separated positive integers A and B.
Corresponding to each test case, in a new line, print the value of f(AB).
1 ≤ T ≤ 200
1 ≤ A, B ≤ 109
f(66) = f(46656) = f(27) = f(9) = 9
f(73) = f(343) = f(10) = f(1) = 1
f(1000) = f(1) = 1
If you have purchased any course from GeeksforGeeks then please ask your doubt on course discussion forum. You will get quick replies from GFG Moderators there.