调了好几次，还是过不了啊啊啊！！

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const long long INF=92e17;
ll n,L,a[33];
bool ck(ll m){
	ll Ans=0;
	for(ll i=n-1;i>=0;i--){Ans+=(m/a[i])*(1<<i);m%=a[i];}
	return Ans>=L;
}
int main(){
	cin>>n>>L;
	for(ll i=0;i<n;i++){
		cin>>a[i];if(!i)continue;
		a[i]=min(a[i-1]*2,a[i]);
	}
	ll l=1,r=INF,mid;
	while(r>l){
		mid=(l+r)/2;
		if(ck(mid))r=mid;
		else l=mid+1;
	}
	cout<<l<<endl;
	return 0;
}