Maximum marks of five exams E1, E2, E3, E4 and E5 are compared. Maximum marks of each exam are different. Maximum marks of E5 are more than E3 and maximum marks of E3 are more than E1. Maximum marks of E1 are more than E4 and E2. Maximum marks of E2 are not the least among them. If the maximum marks of E2 are 180, then what can be the maximum marks of E4?