Find the frequency of the letter "c" in the following sentence. Output the frequency.
I accidentally dropped my phone on the ground.
The letter "c" appears 1 time in the sentence "I accidentally dropped my phone on the ground."
Complete the following task based on the instruction and optional input provided.### Instruction:
Find the frequency of the letter "c" in the following sentence. Output the frequency.

### Input:
I accidentally dropped my phone on the ground.

### Output:
The letter "c" appears 1 time in the sentence "I accidentally dropped my phone on the ground."