CF1211C Ice Cream

Tanya 想在 $n$ 天内吃掉 $k$ 份冰淇凌，在第 $i$ 天她至少吃 $a_i$ 份，至多吃 $b_i$ 份，冰淇凌的价格为 $c_i$，当天买必须当天吃完，求最少的花费。

第一行两个整数 $n$ 和 $k$. 接下来 $n$ 行每行三个整数 $a_i$, $b_i$, $c_i$.

输出最小花费。如果无解输出 -1. （请使用 Kotlin 语言）

In the first example, Tanya needs to eat $ 3 $ portions of ice cream on the first day, $ 1 $ portions of ice cream on the second day and $ 3 $ portions of ice cream on the third day. In this case, the amount of money spent is $ 3\cdot6+1\cdot4+3\cdot3=31 $ . It can be shown that any other valid way to eat exactly $ 7 $ portions of ice cream costs more.