my code 169668033

getting TLE in test 2, have used fast_IO and verified this time complexity with solution solution blogalso.. have used same logic

what I am doing wrong here..

def remove(arr, ele):
    arr.remove(ele)
    return arr
    
t = int(input())
for _ in range(0, t):
    n = int(input())
    
    a = []
    op = []
    for i in range(1, n+1):
        a.append(i)
    
    # print(a)
    for i in range(0, n-1):
        # a.sort()
        x = a[-1]
        y = a[-2]
    
        a.append(round( (x+y)/2) )
        op.append([x,y])
        a = remove(a, x)
        a = remove(a, y)
 
    sys.stdout.write(str(a[0]) + "\n")
    for i in op:
        sys.stdout.write(" ".join(map(str,i)) + "\n")