Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the highest score for candidate Mohsen Rezaee when  candidate mir-hossein mousavi  scored 837858 votes?

### Inputs:
table_name: table, columns: ['Province', 'Mahmoud Ahmadinejad', 'Mehdi Karroubi', 'Mir-Hossein Mousavi', 'Mohsen Rezaee', 'Spoiled ballots', 'Total votes']

### Response:
SELECT MAX Mohsen Rezaee FROM table WHERE Mir-Hossein Mousavi = 837858