CF140A.New Year Table

Gerald is setting the New Year table. The table has the form of a circle; its radius equals R. Gerald invited many guests and is concerned whether the table has enough space for plates for all those guests. Consider all plates to be round and have the same radii that equal r. Each plate must be completely inside the table and must touch the edge of the table. Of course, the plates must not intersect, but they can touch each other. Help Gerald determine whether the table is large enough for n plates.

杰拉尔德正在布置新年餐桌。餐桌呈圆形，半径为 $R$。杰拉尔德邀请了许多客人，他担心餐桌是否能为所有客人摆放足够的餐盘。假设所有餐盘均为圆形，且半径均为 $r$。每个餐盘必须完全置于餐桌内部，并且必须与餐桌边缘相切。当然，餐盘之间不能相交，但可以互相相切。请帮助杰拉尔德判断：该餐桌是否足以摆放 $n$ 个餐盘？

The first line contains three integers n, R and r (1 ≤ n ≤ 100, 1 ≤ r, R ≤ 1000) — the number of plates, the radius of the table and the plates' radius.

第一行包含三个整数 $n$、$R$ 和 $r$（$1 ≤ n ≤ 100$，$1 ≤ r, R ≤ 1000$）—— 分别表示盘子的数量、桌子的半径以及盘子的半径。

Print "YES" (without the quotes) if it is possible to place n plates on the table by the rules given above. If it is impossible, print "NO".

Remember, that each plate must touch the edge of the table.

如果能按照上述规则将 n 个盘子放置在桌子上，则输出 "YES"（不带引号）；否则输出 "NO"。

注意：每个盘子都必须与桌子边缘接触。

The possible arrangement of the plates for the first sample is:

第一个样例中盘子的可能排列方式为：