INF = 1<<64
N,V = map(int,input().split())
C = list(map(int,input().split()))
S = [0] * (N + 1)
for i in range(N):
    S[i+1] = S[i] + C[i]
if V <= N:
    print(S[N])
    exit()
x = 1
for i in range(2,N+1):
    if S[i] / i < S[x] / x:
        x = i
DP = [INF] * (1<<16)
DP[0] = 0
for i in range(1,N+1):
    for L in range(1<<16):
        if L - i >= 0:
            DP[L] = min(DP[L-i] + S[i], DP[L])
V -= N
ans = INF
for i in range(1,N+1):
    K = V // i
    while V - (K * i) <= (1<<10) and K:
        K -= 1
    ans = min(ans, S[i] * K + DP[V - (K * i)] + S[N])
print(ans)