#include <iostream>
#include <cstdio>
using namespace std;
int main(){
    char *foo = "hello";
    char *test = "how are";
    char *concat;
    sprintf(concat, "%s%s", foo, test);
    //int num = 100;
    //sprintf(concat, "%s%s%n", foo, test, num);
    cout << concat;
    return 0;
}