表を作成するのが面倒 + 特別なテストデータ
//============================================================================
// 名前 : Recover Factorial.cpp
// 日付 : 2013/4/23 午前7:19:33
// 著者 : GCA
//============================================================================
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
using namespace std;
#ifdef ONLINE\_JUDGE
#define ll "%lld"
#else
#define ll "%I64d"
#endif
typedef unsigned int uint;
typedef long long int Int;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\\n")
#define I\_de(x,n)for(int i=0;i<n;i++)printf("%d ",x\[i\]);Pln()
#define De(x)printf(#x"%d\\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\\
printf("%d ",dp\[htx\]\[hty\]);}Pln();}
#define M (2705000)
#define PII pair<int,int\>
#define PB push\_back
#define oo INT\_MAX
#define Set\_oo 0x3f
#define Is\_debug true
#define debug(...) if(Is\_debug)printf("DEBUG: "),printf(\_\_VA\_ARGS\_\_)
#define FOR(it,c) for(\_\_typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define eps 1e-6
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
int min3(int x,int y,int z){
int tmp=min(x,y);
return min(tmp,z);
}
int max3(int x,int y,int z){
int tmp=max(x,y);
return max(tmp,z);
}
int seize\[M\];
int bs(int k){
int l=0,r=M-1;
if(k==0)return 0;
while(r>=l){
int mid=(l+r)>>1;
// debug("mid %d ans %d\\n",mid,ans\[mid\]);
if(seize\[mid\]==k){
return mid;
}else if(seize\[mid\]>k)r=mid-1;
else l=mid+1;
}
return -1;
}
void pre(){
// fill(&rans\[0\],&rans\[M-1\],oo);
Set(seize,0);
for(int i=2;i<M;i++){
if(!seize\[i\])seize\[i\]=1;
int k;
for(int j=2;(k=i\*j)<M&&j<=i;j++){
if(seize\[j\]==1)
seize\[k\]=seize\[j\]+seize\[i\];
}
}
for(int i=2;i<M;i++){
// printf("%d,%d\\n",i,seize\[i\]);
seize\[i\]+=seize\[i-1\];
}
}
int main() {
ios\_base::sync\_with\_stdio(0);
pre();
int n,ff=0;
while(~scanf("%d",&n)&&n>=0){
int bsn=bs(n);
if(bsn!=-1)printf("ケース %d: %d!\\n",++ff,bsn);
else printf("ケース %d: 不可能です。\\n",++ff);
}
}