Codeforces-SolutionsA/Codes/1818 B - Indivisible/1818B.cpp

30 lines
457 B
C++
Raw Normal View History

2023-06-28 04:38:26 +08:00
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
void solve()
{
int n;
cin>>n;
if(n==1) cout<<"1"<<endl;
else if(n%2!=0) cout<<"-1"<<endl;
else
{
for(int i=1; i<=n; i+=2)
{
cout<<i+1<<" "<<i<<" ";
}
cout<<endl;
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int TC = 1;
cin >> TC;
cin.ignore();
while (TC--) solve();
}