100 geese
Let's revisit a classic arithmetic puzzle.
*Imagine a flock of geese in flight when a lone goose approaches them. "Greetings, **100** geese," the newcomer says. The leader of the flock responds, "We are not **100** geese. If our number were doubled, then increased by half, then by a quarter, and finally, with you joining us, we would indeed be **100**. How many geese are in our flock?"*
You might recall the answer: there were **36** geese. Now, let's add a twist to this problem.
A flock of geese is flying, and a single goose approaches them. "Greetings, **N** geese," the goose says. The leader of the flock replies, "We are not **N** geese. If our number were doubled, then increased by half, then by a quarter, and with you joining us, we would be **N**." Given a natural number **N**, determine how many geese are in the flock.
Input
The input consists of a single natural number **N** (1 ≤ **N** ≤ 2·10^9).
Output
If it's possible to determine a whole positive number of geese in the flock for the given **N**, output that number. Otherwise, output **-1**.