With what initial speed was the stone thrown down from a height of 10 m if it reached the ground

With what initial speed was the stone thrown down from a height of 10 m if it reached the ground in 1 s? Acceleration of free fall is considered 10 m / s ^ 2.

H = 10 m – flight altitude
t = 1 sec
a = g = 10 m / s ^ 2
V0 -?
the path traversed by the body during free fall down is found by the formula:
S = V0 * t + a * t ^ 2/2
the path traveled by the body is equal to the flight altitude S = H
V0 * t = H – g * t ^ 2/2
V0 = (H – g * t ^ 2/2) / t
V0 = (10 – 10 * 1 ^ 2/2) / 1 = 5 m / s
Answer: V0 = 5 m / s