Identify if the following sentence is present perfect or present simple. Output 1 for present perfect, and 0 for present simple.
I have heard this song before.
1
Complete the following task based on the instruction and optional input provided.### Instruction:
Identify if the following sentence is present perfect or present simple. Output 1 for present perfect, and 0 for present simple.

### Input:
I have heard this song before.

### Output:
1