[redhead]

#include <stdio.h>

int main(){
  char* hello={"Hello "};
  char* world={"world"};
  char hello_world[50];
  int index_hello=0, index_world=0;
  while(hello[index_hello])
    hello_world[index_hello]=hello[index_hello++];
  while(world[index_world])
    hello_world[index_hello++]=world[index_world++];
  hello_world[index_hello]='\0';
  printf("%s\n", hello_world);
  return 1;
}