#include <stdio.h>
int top =-1;
void push ()
int main()
    if (top = -1)
    {
        for(top== -1; top<n;top++)
        {
            printf("%d",stack[n])
        }
    }
    int n;
    if(n < 0)
    {
        printf("Invalid input");
    }
    else
    {
        int stack[n];
        int (top == -1);
        {
            push();
        }
    }
}