题目描述Description

Measuring the area of a certain shape is an important part of certain geometric problems. For a point A(x,y) on the plane, we define the F(x,y) as |x|*|y|,which means the area of the rectangle with the vertex(x, 0),(y, 0),(0, 0),(x, y). You are given n∗ m vertex with integral coordinates in the form of ( i, j ),and 1 ≤ i ≤ n, 1 ≤ j ≤ m. You need to find the K-th biggest value of F(i,j),when 1 ≤ i ≤ n, 1 ≤ j ≤ m. It’s guranteed that K ≤ n ∗ m

输入格式Input

Three integers n, m, K(1 ≤ n, m, K ≤ 1e6)

输出格式Output

One integer,the K-th biggest value of F(i, j).

样例Sample

提示Hint

In this eaxmple, the values of all F(i, j) are 1,2,2,3,3,4,6,6,9. So the 4-th biggest value of F(i, j) is 4.

来源Source