PAT-A1103

#include<stdio.h>
#include<vector>
using namespace std;
int n, k, p, max_facsum=-1;
vector<int> fac, temp, ans;
int get_p(int a){
	int loop=0, ans=1;
	while(loop<p){ans=ans*a; loop++;}
	return ans;
}
void DFS(int index, int nowk,int sum, int facsum){
	if(nowk>k || sum>n)return;
	if(nowk==k && sum==n && facsum>max_facsum){
		max_facsum=facsum;		ans=temp;
	}
	if(index>0){
		temp.push_back(index);
		DFS(index,nowk+1,sum+fac[index],facsum+index);  //选
		temp.pop_back();
		DFS(index-1,nowk,sum,facsum);  //不选
	}
}
int main(){
int i=0, tt=0;
scanf("%d%d%d",&n,&k,&p);
while(tt<=n){
	tt=get_p(i++);
	fac.push_back(tt);
}
DFS(fac.size()-1,0,0,0);
if(max_facsum==-1)printf("Impossible\n");
else {
	printf("%d = %d^%d",n,ans[0],p);
	for(i=1;i<ans.size();i++)
		printf(" + %d^%d",ans[i],p);
}
return 0;
}