#include <stdio.h>

//void compare_size(int* a, int* b);

void scan_file(FILE* fp1, FILE* fp2, FILE* fp3);

int main(int argc, char* argv[]) {
    FILE* fp1;
    FILE* fp2;
    FILE* fp3; // eventually

    //first bookend
    fp1 = fopen("numbers1.txt", "r");//creates numbers1.txt
    fp2 = fopen("numbers2.txt", "r");//creates numbers2.txt
    fp3 = fopen("output.txt", "w");//creates number3.txt

    //checks if file1 opened, if not, exit
    if (fp1 == NULL) {
        printf("Failed to open file 1");
        exit(0);//exits with error
    }

    //checks if file 2 opened
    if (fp2 == NULL) {
        printf("Failed to open file 2");
        exit(0);//exits with error
    }

    if (fp3 == NULL) {
        printf("Failed to open file 3");
        exit(0);
    }

    scan_file(fp1, fp2, fp3);

    //second bookend
    fclose(fp1); fp1 = NULL;
    fclose(fp2); fp2 = NULL;
    fclose(fp3); fp3 = NULL;

    return 0;
}

void scan_file(FILE* fp1, FILE* fp2, FILE* fp3) {
    int x, y, smaller,larger;
    int noc1, noc2;

    noc1 = fscanf(fp1, "%d", &x);
    noc2 = fscanf(fp2, "%d", &y);

    do {


            if (noc1 == 1 || noc2 == 1) {
                if (x < y) {
                    smaller = x;
                    noc1 = fscanf(fp1, "%d", &x);
                  //  larger = y;
                    //  noc2 = fscanf(fp2, "%d", &y);

                }

                else {
                    smaller = y;
                    noc2 = fscanf(fp2, "%d", &y);
                    //larger = x;
                  // noc1 = fscanf(fp1, "%d", &x);

                }

            fprintf(fp3, "%d\n", smaller);
          //  fprintf(fp3, "%d\n", larger );

            while (noc1 == 1) {

                fprintf(fp3, "%d\n", x);
                noc1 = fscanf(fp1, "%d", &x);
            }

            while (noc2 == 1) {

                fprintf(fp3, "%d\n", y);
                noc2 = fscanf(fp2, "%d", &y);

            }


        }

    } while (noc1 == 1 || noc2 == 1);

}