Whyit is showing SIGTSTP

Why it is showing time limit exceeded = 1.01seconds?
if it is showing time taken: 0.01 seconds while running.
problem = Contest Page | CodeChef
solution = Solution: 50123791 | CodeChef

The time complexity of your code is O(N) per test case, where N spans all possible values for the LCM. Might I suggest you look into a more efficient algorithm to calculate the GCD?

Also note that once you have the GCD, the LCM can trivially be calculated using the formula LCM = A * B / GCD.