Edit this paragraph for correct grammar.
This is a difficult problem and require a lot of time to solve
This is a difficult problem and requires a lot of time to solve.
Complete the following task based on the instruction and optional input provided.### Instruction:
Edit this paragraph for correct grammar.

### Input:
This is a difficult problem and require a lot of time to solve

### Output:
This is a difficult problem and requires a lot of time to solve.