import sys
n, v = map(int, input().split())
c = list(map(int, input().split()))
sum_ = [0] * (n + 1)
for i in range(n):
    sum_[i + 1] = sum_[i] + c[i]
if v <= n:
    print(sum_[n])
    sys.exit(0)
dp = [sys.maxsize] * 20001
dp[0] = 0
for i in range(20000):
    for j in range(1, n + 1):
        if i + j <= 20000:
            dp[i + j] = min(dp[i + j], dp[i] + sum_[j])
if v <= 20000:
    ret = sum_[n] + dp[v - n]
    print(ret)
    sys.exit(0)
m = v - n - 15000
ret = sys.maxsize
for i in range(1, n + 1):
    a = m // i
    b = 15000 + m % i
    ret = min(ret, sum_[n] + sum_[i] * a + dp[b])
print(ret)