C :

#include<stdio.h>
#include<string.h>
int main()
{
	char a[202],b[102];
	int i,k,l1,l2;
	gets(a);
	gets(b);
	l1=strlen(a);
	l2=strlen(b);
	for(k=0,i=l1;i<(l1+l2)&&k<l2;i++)
		a[i]=b[k++];
	a[l1+l2]='\0';
	puts(a);
	return 0;
}

C++ :

#include <stdio.h>
#include <string.h>
int main() {
	char str[2][101], newstr[201];
	int i, j, length = 0;
	for (i = 0;i < 2;i++)
		gets(str[i]);
	for (i = 0;i < 2;i++) {
		for (j = 0;str[i][j] != '\0';j++) {
			newstr[length++] = str[i][j];
		}
	}
	newstr[length] = '\0';
	puts(newstr);
	return 0;
}

Pascal :

var
  a,b:string;
begin
  readln(a);
  readln(b); 
  writeln(a+b);
end.

Java :

import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		String s1=in.nextLine();
		String s2=in.nextLine();
		System.out.println (s1+s2);
	}	
}

Python :

a = raw_input()
b = raw_input()
print (a+b)