import sys

INF = 10**18
N, V = map(int, input().split())
A = list(map(int, input().split()))
Sum = [0] * (N + 1)

for i in range(N):
    Sum[i + 1] = Sum[i] + A[i]
if V <= N:
    print(Sum[N])
    sys.exit()

best = 1
for i in range(2, N + 1):
    if Sum[i] / i < Sum[best] / best:
        best = i

dp = [INF] * (best * N + 1)
dp[0] = 0
for R in range(1, N + 1):
    for prevSum in range(len(dp) - R):
        dp[prevSum + R] = min(dp[prevSum + R], dp[prevSum] + Sum[R])

ans = INF
V -= N
for i in range(len(dp)):
    if (V - i) % best == 0:
        ans = min(ans, dp[i] + (V - i) // best * Sum[best])
ans += Sum[N]

print(ans)