INF = 1<<100
N,V = map(int,input().split())
C = list(map(int,input().split()))
S = [0] * N
for i in range(N):
    S[i] = S[i-1] + C[i]
if V <= N:
    print(S[-1])
    exit()
DP = [[INF] * 101 for _ in range(N+1)]
DP[0][0] = 0
for i in range(N):
    for j in range(101):
        DP[i+1][j] = min(DP[i][j], DP[i+1][j])
        k = min(100, (i + 1) + j)
        DP[i+1][k] = min(DP[i][j] + S[i], DP[i+1][j] + S[i], DP[i+1][k])
V -= N
ans = INF
for i in range(N):
    ans = min(ans, (S[i] * (V // (i + 1))) + (DP[N][V % (i + 1)]) + S[-1])
print(ans)