What will be the output of the following code?

#include stdio.h
int main() 
{
  int num = 7, i;
  unsigned long long fact = 1;
  if (num  0)
    printf("Error! Factorial of a negative number doesn't exist.");
  else 
  {
    for (i = 1; i = num; i++) {
      fact *= i;
    }
    printf("Factorial of %d = %llu", num, fact);
  }
  return 0;
}