CF1141E.Superhero Battle

A superhero fights with a monster. The battle consists of rounds, each of which lasts exactly $n$ minutes. After a round ends, the next round starts immediately. This is repeated over and over again.

Each round has the same scenario. It is described by a sequence of $n$ numbers: $d_1, d_2, \dots, d_n$ ($-10^6 \le d_i \le 10^6$). The $i$-th element means that monster's hp (hit points) changes by the value $d_i$ during the $i$-th minute of each round. Formally, if before the $i$-th minute of a round the monster's hp is $h$, then after the $i$-th minute it changes to $h := h + d_i$.

The monster's initial hp is $H$. It means that before the battle the monster has $H$ hit points. Print the first minute after which the monster dies. The monster dies if its hp is less than or equal to $0$. Print -1 if the battle continues infinitely.

一位超级英雄与一只怪物展开战斗。战斗由若干轮组成，每轮持续恰好 $n$ 分钟。一轮结束后，下一轮立即开始，如此循环往复。

每轮的战斗情景完全相同，由一个长度为 $n$ 的数字序列描述：$d_1, d_2, \dots, d_n$（其中 $-10^6 \le d_i \le 10^6$）。第 $i$ 个元素表示：在每轮的第 $i$ 分钟内，怪物的生命值（hp，即“击中点数”）变化量为 $d_i$。形式化地说，若某轮第 $i$ 分钟开始前怪物的生命值为 $h$，则第 $i$ 分钟结束后其生命值变为 $h := h + d_i$。

怪物的初始生命值为 $H$，即战斗开始前其生命值为 $H$。请输出怪物死亡后的第一分钟（即从战斗开始起算的分钟编号，从第 $1$ 分钟起计）。当怪物生命值小于等于 $0$ 时，视为死亡。若战斗无限持续下去，请输出 $-1$。

The first line contains two integers $H$ and $n$ ($1 \le H \le 10^{12}$, $1 \le n \le 2\cdot10^5$). The second line contains the sequence of integers $d_1, d_2, \dots, d_n$ ($-10^6 \le d_i \le 10^6$), where $d_i$ is the value to change monster's hp in the $i$-th minute of a round.

第一行包含两个整数 $H$ 和 $n$（$1 \le H \le 10^{12}$，$1 \le n \le 2\cdot10^5$）。第二行包含整数序列 $d_1, d_2, \dots, d_n$（$-10^6 \le d_i \le 10^6$），其中 $d_i$ 表示在一轮中的第 $i$ 分钟对怪物生命值（HP）的改变量。

Print -1 if the superhero can't kill the monster and the battle will last infinitely. Otherwise, print the positive integer $k$ such that $k$ is the first minute after which the monster is dead.

如果超级英雄无法杀死怪物，战斗将无限持续，则输出 $-1$。否则，输出正整数 $k$，使得 $k$ 是怪物死亡后的第一分钟。