#include <stdio.h>
#define Nums 21
#include <iostream>
using namespace std;

int main (void){
int numbers [Nums]={0};
int isDuplicate, user_input;
int a,z;

int numberofinputs = 0;

cout << "Please enter 21 numbers" << endl;

for (a=0; a<= Nums-1, a++)
    isDuplicate=0;
scanf ("%d", &user_input);

for (z=0; z<numberofinputs; z++){
    if(user_input =numbers[z]){
        isDuplicate=1;
        break;

    }
}
if(!isDuplicate){

    numbers[numberofinputs++]=user_input;

}
}

cout << "Non duplicate numbers are " << endl;

for (a=0; a<Nums && numbers[a]!=0;a++){

    cout << "(%d,numbers [a]" << endl;

}