why is this code failing here — run time error — with no further details. It is working without any problem on my IDE. ~~~~~ for _ in range(int(input())): arr = [int(x) for x in input().split()] noq = int(input()) for _ in range(noq): l, r, x, y = [int(x) for x in input().split()] l-=1 for i in range(l, r): if arr[i]==x:arr[i]=y print(*arr) ~~~~~ I can understand if it get TLE or some other error. But runtime error. Besides all submissions have either C++ or java so there is no way to know what i am doing wrong.