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()
V -= N
x = 1
for i in range(2,N+1):
    if S[i] / i < S[x] / x:
        x = i
K = V // x
while V - (K * x) <= 20000 and K:
    K -= 1
V -= K * x
DP = [[INF] * (V+1) for _ in range(N+1)]
DP[0][0] = 0
for i in range(1,N+1):
    for j in range(V+1):
        DP[i][j] = min(DP[i-1][j], DP[i][j])
        k = j - i
        DP[i][j] = min(DP[i][k] + S[i], DP[i][j])
print(S[x] * K + DP[N][V] + S[N])