1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
#include <cmath>
#include <cstring>
#include <iostream>
#include <vector>

using namespace std;

vector<int> p;
typedef unsigned long long ull;
ull N;
int k;
vector<int> w;

const int C = 7  * (1 << 17);
ull a[C];
ull best = 0;

void ks() {
    memset(a, 0, sizeof(a));
    a[0] = -1;
    for(int i=0; i<k; i++)
        for(int r=0; r<w[i]; r++) {
            ull mark=0;
            for(int j=r; j<C; j+=w[i])
                if(mark) a[j]|=1ULL<<i;
                else mark|=a[j];
        }
}

void construct(int j, int i, ull c) {
    if(i==0) {
        if(c<=N) best=max(c, best);
        return;
    }
    for(; j>=0; j--)
        if(a[i]&(1ULL<<j))
            construct(j, i - w[j], c * p[j]);
}

void find(int i) {
    if(a[i])
        construct(k-1, i, 1);
}

int main() {
    cin >> k >> N;
    p.resize(k);
    for(int i=0; i<k; i++)
        cin >> p[i];
    // scale * log(N) = C - 64
    double scale = (C - 64) / log(N);
    w.resize(k);
    for(int i=0;i<k;i++)
        w[i] = round(scale * log(p[i]));
    ks();
    int x=C-1;
    while(a[x]==0)
        x--;
    int y=0;
    for(int i=x; i>=y; i--) {
        find(i);
        if(best && y==0)
            y=i-32;
    }
    cout << best << endl;
}