#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <string.h>

pid_t childPidL, childPidR;

int main(int argc, char* argv[]) {
        char *str = argv[1];
        char *pStr = "";
        if(argv[2] != NULL) asprintf(&pStr, "%s", argv[2]);
        int len = strlen(str);
        asprintf(&pStr, "%s %s", pStr, str);
        if (len > 1) {
                int halfLen = (len/2);

                char *strLeft = (char*)malloc((halfLen+1) * sizeof(char));
                strncpy(strLeft, str, halfLen);
                childPidL = fork();
                if (!childPidL) {
                        execl("./main", "main", strLeft, pStr, NULL);
                }

                char *strRight = (char*)malloc((halfLen+1) * sizeof(char));
                strncpy(strRight, str+halfLen, halfLen);
                childPidR = fork();
                if (!childPidR) {
                        execl("./main", "main", strRight, pStr, NULL);
                }
                wait(NULL);
                wait(NULL);
                free(strLeft);
                free(strRight);
                free(pStr);
        }
        printf("%s\n", pStr);
        return 0;
}