def d():
n, k = list(map(int, input().split()))
a = list(map(int, input().split()))
a.sort()
curr = a[0]
for i in range(1, n):
c = min(a[i]-curr, k//i)
curr += c
k -= c*i
if k == 0:
break
return (curr*n+(k+sum(x > curr for x in a)))-(n-1)
for i in range(int(input())):
print(d())
1644B - Anti-Fibonacci Permutation | 1610A - Anti Light's Cell Guessing |
349B - Color the Fence | 144A - Arrival of the General |
1106A - Lunar New Year and Cross Counting | 58A - Chat room |
230A - Dragons | 200B - Drinks |
13A - Numbers | 129A - Cookies |
1367B - Even Array | 136A - Presents |
1450A - Avoid Trygub | 327A - Flipping Game |
411A - Password Check | 1520C - Not Adjacent Matrix |
1538B - Friends and Candies | 580A - Kefa and First Steps |
1038B - Non-Coprime Partition | 43A - Football |
50A - Domino piling | 479A - Expression |
1480A - Yet Another String Game | 1216C - White Sheet |
1648A - Weird Sum | 427A - Police Recruits |
535A - Tavas and Nafas | 581A - Vasya the Hipster |
1537B - Bad Boy | 1406B - Maximum Product |