The monster needs to walk a distance of 1000m, and the movement speed of the monster is 10m/s

In the 3rd second, player A uses a buff on the monster, and the monster starts to perform a uniform acceleration movement with an acceleration of 5m/s, which lasts for 5s

At the 5th s, player B applies a buff to the monster, and the monster starts to perform a uniform acceleration motion with an acceleration of 2m/s, which lasts for 3s

At the 7th s, player C uses a buff on the monster, and the monster starts to perform a uniform deceleration movement with an acceleration of -3m/s, which lasts for 2s

Find the time it takes for the monster to move 1000m

Note: The buff is superimposed, that is, at the 5th second, the monster has two accelerations