Modify the given sentence by replacing the underlined words with synonyms.
The old man was irate with the slow progress of the project.
The elderly man was furious with the sluggish advancement of the project.
Complete the following task based on the instruction and optional input provided.### Instruction:
Modify the given sentence by replacing the underlined words with synonyms.

### Input:
The old man was irate with the slow progress of the project.

### Output:
The elderly man was furious with the sluggish advancement of the project.