Help me in solving KO_MON problem

help
,
1

My issue

my code gives correct output for every situation where it is failing ? help me

My code

# cook your dish here
tc = int(input())
for i in range(tc):
    monster ,hpi = map(int,input().split())
    c_hp = list(map(int,input().split()))
    c_hp.sort()
    max_hit = c_hp[0] + ((monster - 1) * hpi)
    max_hit=max(c_hp[-1],max_hit)
    print(max_hit)

Problem Link: Monster Monster Practice Coding Problem