rt。谢谢。

#include<bits/stdc++.h>
#define int long long
using namespace std;
int f(int x){
	int y=0;
	while(x!=0) y=y*10+x%10,x/=10;
	return y;
}
int siz(int x){
	int k=0;
	while(x!=0) k++,x/=10;
	return k;
}
int n,a[1000005],top1,b[1000005],top2;
void print(){
	if(top1+top2<=1){
		cout<<-1;
		exit(0);
	}
	for(int i=1;i<=top1;i++) cout<<a[i]<<"*";
	for(int i=top2;i>1;i--) cout<<b[i]<<"*";
	cout<<b[1];
	exit(0);
}
bool check(int x){
	while(x!=0){
		if(x%10==0) return 0;
		x/=10;
	}
	return 1;
}
void dfs(int x){
	if(x==1) print();
	if(check(x)&&x==f(x)&&top1+top2>1){
		a[++top1]=x;
		print();
	}
	for(int i=2;i*i<=x;i++){
		if(!(check(i))) continue;
		if(x%i==0&&(x/i)%f(i)==0){
			a[++top1]=i,b[++top2]=f(i);
			dfs(x/i/f(i));
			top1--,top2--;
		}
	}
}
signed main(){
	cin>>n;
	dfs(n);
	print();
	return 0;
}