Help me in solving MAXSCP problem

help
,
1

My issue

Kindly help me to understand the issue with the code

My code

for i in range(int(input())):
    N = int(input())
    J = []
    for i in range(N):
        K = list(map(int,input().split()))
        J.append(K)
    J.sort()
    #print(J)
    i = 0
    while i < N:
        for k in range(N-1):
            if J[i][k] > J[i][k +1]:
                J[i][k] ,J[i][k +1] =J[i][k+1] , J[i][k]
        i += 1
    #print(J)
    M = []
    o = 0
    while o < N:
        M.append(J[o][N-1])
        o = o+1
    M.sort()
    Ans = True
    for i in range(N-1):
        if M[i] == M[i+1]:
            Ans = False
    if Ans:        
        print(sum(M))
    else:
        print("-1")

Learning course: Greedy Algorithms
Problem Link: Maximum Score Practice Problem in Greedy Algorithms - CodeChef