112860.cpp

#include <iostream>

using namespace std;

typedef vector<int> vi;
typedef long long int lli;

int main(){

    int n, max, l, r;
    cin >> n;
    max = (n / 4 + (bool)(n % 4)) * 4;
    l = 1;
    r = max;
    while (l < r){
        if (r > n)
            cout << "-";
        else
            cout << r;
        cout << " ";
        if (l > n)
            cout << "-";
        else
            cout << l;
        l += 2;
        r -= 2;
        if (l < r)
            cout << " ";
        else
            cout << endl;
    }
    l = 2;
    r = max - 1;
    while (l < r){
        if (l > n)
            cout << "-";
        else
            cout << l;
        cout << " ";
        if (r > n)
            cout << "-";
        else
            cout << r;
        l += 2;
        r -= 2;
        if (l < r)
            cout << " ";
        else
            cout << endl;
    }

    return 0;
}