https://ideone.com/GTEcDT

#include <iostream>

//#include <stdio.h>      //Not required in VC++

//#include <stdlib.h>     //Not required in VC++

#include <time.h>

static int NotEvenMult(int N) {

   int result = 1, count=0;

   while (N) {  

       if ((N % 10) % 2 != 0) { count++; result *= (N % 10); }

       N /= 10; }

   if (count > 0) return result; return -1;

}

...

srand(time(NULL));

cout << NotEvenMult(rand())<<endl;