import sys
from itertools import accumulate
read=sys.stdin.buffer.read

N,V,*C=map(int,read().split())
C=tuple(accumulate(C))
V-=N
ans=C[-1]

INF=10**20
LIM=10010
dp=[INF]*LIM
dp[0]=0

for i,x in enumerate(C,1):
	for j in range(i,LIM):
		cst=dp[j-i]+x
		if dp[j]>cst:dp[j]=cst

rate=[x/i for i,x in enumerate(C,1)]
n=rate.index(min(rate))+1

k=max(0,1+(V-LIM)//n)
ans+=k*C[n-1]
if V>0:ans+=dp[V-k*n]
print(ans)