10085: ABC346 —— C - Σ
[Creator : ]
Description
You are given a sequence of positive integers $A=(A_1,A_2,\dots,A_N)$ of length $N$ and a positive integer $K$.
Find the sum of the integers between $1$ and $K$, inclusive, that do not appear in the sequence $A$.
Find the sum of the integers between $1$ and $K$, inclusive, that do not appear in the sequence $A$.
Input
The input is given from Standard Input in the following format:
```
$N$ $K$
$A_1$ $A_2$ $\dots$ $A_N$
```
```
$N$ $K$
$A_1$ $A_2$ $\dots$ $A_N$
```
Output
Print the answer.
Constraints
- $1\leq N \leq 2\times 10^5$
- $1\leq K \leq 2\times 10^9$
- $1\leq A_i \leq 2\times 10^9$
- All input values are integers.
- $1\leq K \leq 2\times 10^9$
- $1\leq A_i \leq 2\times 10^9$
- All input values are integers.
Sample 1 Input
4 5
1 6 3 1
Sample 1 Output
11
Among the integers between 1 and 5, three numbers, 2, 4, and 5, do not appear in A.
Thus, print their sum: 2+4+5=11.
Sample 2 Input
1 3
346
Sample 2 Output
6
Sample 3 Input
10 158260522
877914575 24979445 623690081 262703497 24979445 1822804784 1430302156 1161735902 923078537 1189330739
Sample 3 Output
12523196466007058