#include <iostream>
using namespace std;

class LowerTri 
{
    private :
        int n; 
        int *A;
 
    public :
    
     LowerTri(int n)
        {
            this->n = n;
            A = new int[(n*(n+1))/2];
        }
 
        void set (int i, int j , int x);
        int get (int i, int j);
        void display();
         LowerTri()
        {
            delete []A;
        }
};
 
void LowerTri :: set(int i, int j, int x)
{
    if(i>=j)
        A[(i*(i-1)/2) + (j-1)] = x;
}
 
int LowerTri :: get(int i ,int j)
{
    if(i>=j)
        return A[(i*(i-1)/2) + (j-1)];
    else 
        return 0;
}
 
void LowerTri :: display()
{
//    cout << "\n\n";
    for (int i=1; i<=n; i++)
    {
        for (int j=1; j<=n; j++)
        {
            if (i>=j)
                cout << A[(i*(i-1)/2) + (j-1)] << " ";
            else
                cout << "0 ";
        }
        cout << endl;
    }
}

int main() {
    
    int d ;
    cout << "Enter dimensions : " ;
    cin >> d;
    
    LowerTri lm(d);
    
    int x;
    cout << "Enter all elements : " << endl;
    for(int i=1 ; i<=d; i++)
    {
        for (int j=1; j<=d; j++)
        {
            cin >> x;
            lm.set(i,j,x);
        }
    }
    
    cout << "\n\n";
	lm.display();
    return 0;
}