题目描述
You are given a sequence a = \{a_1, ..., a_N\} with all zeros, and a sequence b = \{b_1, ..., b_N\} consisting of 0 and 1. The length of both is N.
You can perform Q kinds of operations. The i-th operation is as follows:
- Replace each of a_{l_i}, a_{l_i + 1}, ..., a_{r_i} with 1.
Minimize the hamming distance between a and b, that is, the number of i such that $a_i \neq b_i$, by performing some of the Q operations.
Constraints
- $1 \leq N \leq 200,000$
- b consists of 0 and 1.
- $1 \leq Q \leq 200,000$
- $1 \leq l_i \leq r_i \leq N$
- If $i \neq j, either l_i \neq l_j$ or $r_i \neq r_j$.
Input
Input is given from Standard Input in the following format:
N
b_1 b_2 ... b_N
Q
l_1 r_1
l_2 r_2
:
l_Q r_Q
Output
Print the minimum possible hamming distance.
Examples
Input
3
1 0 1
1
1 3
Output
1
Input
3
1 0 1
2
1 1
3 3
Output
0
Input
3
1 0 1
2
1 1
2 3
Output
1
Input
5
0 1 0 1 0
1
1 5
Output
2
Input
9
0 1 0 1 1 1 0 1 0
3
1 4
5 8
6 7
Output
3
Input
15
1 1 0 0 0 0 0 0 1 0 1 1 1 0 0
9
4 10
13 14
1 7
4 14
9 11
2 6
7 8
3 12
7 13
Output
5
Input
10
0 0 0 1 0 0 1 1 1 0
7
1 4
2 5
1 3
6 7
9 9
1 5
7 9
Output
1
输入格式
见题面
输出格式
见题面