链接:https://vjudge.net/contest/288256#problem/F
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
using namespace std;
const int sz = 1e7+1;
int prime[sz+1],sr[sz+1],num;
void solve1(){
for(int i = 1;i<=sz;++i){
prime[i] = i;
}
for(long long i = 2;i<=sz;++i){
if(prime[i] == i){
sr[num++] = i;
for(long long j = i*i;j<=sz;j+=i){
prime[j] = 0;
}
}
}
}
int main(){
num = 0;
solve1();
int t,n,ans,id = 0;
scanf("%d",&t);
while(t--){
scanf("%d",&n);
ans = 0;
for(int i = 0;sr[i] <= n/2;++i){
if(prime[n-sr[i]] == (n-sr[i])) ++ans;
}
cout<<"Case "<<++id<<": "<<ans<<endl;
}
return 0;
}