C :

#include<stdio.h>

void main(){
	int i,g,b;
	
	for(i=100;i<=999;i++){
		g=i%10;
		b=i/100;
		if(g==b){
			printf("%d\n",i);
		}
	}
} 

C++ :

#include <bits/stdc++.h>
using namespace std;

int main() {
	int i,n,g,b;
	i = 100;
	while(i <= 999){
		g = i % 10;
		b = i / 100;
		if(g == b){
			cout<<i<<endl;
		}
		i = i + 1;
	}
}

Pascal :

var i,a,b:longint;
begin
for i:=100 to 999 do
begin
a:=i mod 10;
b:=i div 100;
if a=b then writeln(i);
end;
end.

Java :

public class Main {

	public static void main(String[] args) {
		for(int i=100;i<=999;i++) {
			int g = i % 10;
			int b = i / 100;
			if(g==b) {
				System.out.println(i);
			}
		}

	}

}

Python :

for i in range(100, 1000):
    bw = i // 100 % 10
    sw = i // 10 % 10
    gw = i // 1 % 10
    if bw == gw:
        print(i)