#include <iostream>
#include <string>
using namespace std;
#define MAX 255
 
int myStrlen(char s[]);
bool myStrcat(char s1[], char s2[]);
 
int main()
{
	char s1[MAX], s2[MAX];
	cin.getline(s1,MAX);
	cin.getline(s2,MAX);
	bool kt = myStrcat(s1, s2);
 
if (kt==false) cout << "Khong noi duoc. Khong du bo nho.";
    else cout << s1 << s2;
}
 
 
bool myStrcat(char s1[], char s2[]){
    if (myStrlen(s1)+myStrlen(s2)>256) return false;
    return true;
 
}
 
int myStrlen(char s[]){
    int dem = 0;
    for (int i=0;s[i]!='\0';i++) ++dem;
    return dem;
}
 

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