C :

#include<stdio.h>

void main(){
	int i,g,s,b,q,m,n;
	
	for(i=1000;i<=9999;i++){
		g=i%10;
		s=i/10%10;
		b=i/100%10;
		q=i/1000;
		m=s*10+g;
		n=q*10+b;
		if(i==(m+n)*(m+n)){
			printf("%d\n",i); 
		}
	}

}

C++ :

#include <iostream>  
#include<math.h>
using namespace std;  
int main(){  
   int i;
   for(i = 1000;i <= 9999;i++)
   { 
     int a = i / 1000;
     int b = i / 100 % 10;
     int c = i / 10 % 10;
     int d = i % 10;
     int e = a *10 + b;
int f = c *10 + d;
if((e + f) *(e + f)  == i){ 
   cout<<i<<endl;
}
   }
   return 0;  
  } 

Pascal :

var i,a,b:integer;
begin
    i := 1000;
    for i := 1000 to 9999 do
    begin
       a := i div 100;
       b := i mod 100;
       if (a + b) * (a + b) = i then
       writeln(i);
    end;
end.
 

Java :

public class Main {
			 public static void main(String[] args) {
				
				   for (int j=1000; j<=9999; j++) { 
					   int a=j%10000/1000;
					   int b=j%1000/100;
					   int c=j%100/10;
					   int d=j%10;
					   
					   if(((a*10+b)+(c*10+d))*((a*10+b)+(c*10+d))==(a*1000+b*100+c*10+d)) {
						    System.out.println(j);   
					   }
					     
      }
				  
 }
}

Python :

for n in range (1000, 10000):
    a = n // 1000;
    b = n // 100 % 10;
    c = n // 10 % 10;
    d = n % 10;
    if (a*10 + b +c * 10 + d )*(a*10 + b +c * 10 + d)== a * 1000 +b * 100+ c *10 +d:
        print(a * 1000 +b * 100+ c *10 +d)