#!/usr/bin/ python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import itertools

N, V, *C = map(int, read().split())
C = tuple(itertools.accumulate(C))
V -= N
answer = C[-1]

U = 10010
# cost -> value
INF = 10 ** 18
dp = [INF] * U
dp[0] = 0
for i, x in enumerate(C, 1):
    for j in range(i, U):
        c = dp[j - i] + x
        if dp[j] > c:
            dp[j] = c

rate = [x / i for i, x in enumerate(C, 1)]
n = rate.index(min(rate)) + 1

k = max(0, (V - U) // n)
answer += k * C[n - 1]
if V > 0:
    answer += dp[V - k * n]
print(answer)