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

### Instruction:
Which Number of vehicles has a Type designation of u5-25 (bi-directional)?

### Inputs:
table_name: table, columns: ['City', 'Operator', 'Type designation', 'Number of vehicles', 'Width']

### Response:
SELECT Number of vehicles FROM table WHERE Type designation = u5-25 (bi-directional)