#include <stdio.h>
#include <time.h>
#include <string.h>
#include <stdlib.h>

char* genset(int num, int max, int mod) {
    char *temp;
    do {
        temp = (char *)calloc(num+1, sizeof(char));
        for(int i=0; i<num; i++)
            sprintf(temp, "%s%d", temp, (rand()%mod));
    } while(atoi(temp)>max);
    return temp;
}

int main(int argc, char **argv) {
    srand(time(NULL));
    printf("%s-%s-%s\n", genset(3, 999, 8), genset(3, 742, 10), genset(4, 9999, 10));
}