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

### Instruction:
What is the 1986 value with A in 1991 and A in 1987?

### Inputs:
table_name: table, columns: ['Tournament', '1984', '1985', '1986', '1987', '1988', '1989', '1990', '1991', '1992', '1993', '1994', '1995', '1996', '1997', '1998', '1999', '2000']

### Response:
SELECT 1986 FROM table WHERE 1991 = a AND 1987 = a