Steve's scores on Exams #1, #2 and #4 are 89, 93, and 87 (out 0f 100). Unfortunately he skipped Exam #3. This resulted in a score of 0 for him on Exam #3. If he has to get a passing grade of at least 70% to go on to the next class, and he has only Exam #5 left in the class, what is the minimum score he needs to get on Exam #5? Assume his grade is calculated using only 5 exam scores.