就是1的问题，我该了1后40点就通过了

#include <bits/stdc++.h>
using namespace std;
#define FOR(i,n) for (int i=1;i<=n;i++)
#define REP(i,a,b) for (int i=a;i<=b;i++)
#define pb push_back
#define mp make_pair
#define ll long long
#define pos(x,y) (x+(y)*n)
const int N=100000+10;
const int inf=0x3f3f3f3f;
const ll mod=1000000007;
const double eps=1e-8;

int n;
struct bignum {
    int len;
    int a[1000];
    int id;
    bignum () {
        len=0;
        memset(a,0,sizeof a);
    }
    bignum operator*(bignum x) {
        bignum res;
        FOR(i,len) FOR(j,x.len) {
            res.a[i+j-1]+=a[i]*x.a[j];
        }
        FOR(i,len+x.len-1) {
            if (res.a[i]>9) {
                res.a[i+1]+=res.a[i]/10;
                res.a[i]%=10;
            }
        }
        res.len=len+x.len-1;
        if (res.a[res.len+1]) res.len++;
        return res;
    }
    bignum operator=(bignum x) {
        len=x.len;
        FOR(i,len) a[i]=x.a[i];
    }
    bool operator==(bignum &x) {
        if (len==x.len) {
            FOR(i,len) {
                if (a[i]!=x.a[i]) return 0;
            }
            return 1;
        }
        return 0;
    }
};
bignum qpow(bignum a,int b) {
    bignum res;
    res.len=1,res.a[1]=1;
    while (b) {
        if (b&1) res=res*a;
        a=a*a;
        b>>=1;
    }
    return res;
}
void bmax(bignum &x,bignum y) {
    if (x.len>y.len) return;
    if (x.len<y.len) {
        x=y;
        return;
    }
    for (int i=x.len;i>=1;i--) {
        if (x.a[i]<y.a[i]) {
            x=y;
            return;
        } else if (x.a[i]>y.a[i]) break;
    }
}
void print(bignum x) {
    for (int i=x.len;i>=1;i--) cout<<x.a[i];
    cout<<endl;
}
int main() {
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    cin>>n;
    if (n==1) cout<<1<<endl;
    bignum ans,two,three;
    ans.len=1;
    two.len=1,two.a[1]=2;
    three.len=1,three.a[1]=3;
    for (int x=0;x<=n;x++) {
        int y=n-2*x;
        if (y%3||y<0) continue;
        y/=3;
        bignum t=qpow(two,x);
        bmax(ans,t*qpow(three,y));
    }
    print(ans);
    return 0;
}