One hundred and sixty business executives were surveyed to determine whether they regularly visit the CNN Money, Bloomberg, or The Wall Street Journal websites. The survey showed that 70 visit CNN Money, 60 visit Bloomberg, 55 visit The Wall Street Journal, 45 visit exactly two of the three websites, 20 visit CNN Money and Bloomberg, 20 visit Bloomberg and The Wall Street Journal, and 5 visit all three websites. How many do not visit any of the three websites?