Classify the following sentence as a declarative or interrogative sentence: "Do you understand the concept?"
Do you understand the concept?
The given sentence "Do you understand the concept?" is an interrogative sentence.
Complete the following task based on the instruction and optional input provided.### Instruction:
Classify the following sentence as a declarative or interrogative sentence: "Do you understand the concept?"

### Input:
Do you understand the concept?

### Output:
The given sentence "Do you understand the concept?" is an interrogative sentence.