15449번 - Art 다국어

문제

Vera has five sticks of distinct lengths l₁, l₂, l₃, l₄, l₅. Vera may choose any three of the five sticks to form the sides of a triangle. How many different triangles can Vera make? Each triangle must have positive area and sticks cannot be bent or cut.

입력

Line 1 contains integers l₁, l₂, l₃, l₄, l₅ (1 ≤ l_i ≤ 1000).

출력

Print one line with one integer, the number of ways to form a triangle.

제한

힌트

For the first example, the 3 ways to form a triangle are choosing sticks 2, 3, 4 or 2, 4, 5 or 3, 4, 5.