Change the idiomatic expression in the sentence to an appropriate synonym.
He handed in his notice at the drop of a hat.
He handed in his notice abruptly.
Complete the following task based on the instruction and optional input provided.### Instruction:
Change the idiomatic expression in the sentence to an appropriate synonym.

### Input:
He handed in his notice at the drop of a hat.

### Output:
He handed in his notice abruptly.