N,V=map(int,input().split())
C=list(map(int,input().split()))

if V<=N:
    print(sum(C))
    exit()

ANS=sum(C)
V-=N

S=[c for c in C]

for i in range(1,N):
    S[i]+=S[i-1]

MS=[(S[i]/(i+1),i) for i in range(N)]


DP=[1<<100]*(12000)

DP[0]=0

for i in range(N):
    x=S[i]
    c=i+1

    for j in range(12000):
        if j+c<12000 and DP[j+c]>=DP[j]+x:
            DP[j+c]=DP[j]+x

ANS2=1<<100

MIN=min(MS)[1]
plus=S[MIN]

for i in range(12000):
    if i>V:
        break
    rest=V-i

    ANS2=min(ANS2,plus*((rest+MIN)//(MIN+1))+DP[i])

print(ANS+ANS2)