Problem Statement

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.

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.

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 $r_i \neq r_j$.

Sample Input 1

3
1 0 1
1
1 3

Sample Output 1

1

If you choose to perform the operation, a will become {1, 1, 1}, for a hamming distance of 1.

Sample Input 2

3
1 0 1
2
1 1
3 3

Sample Output 2

0

If both operations are performed, a will become {1, 0, 1}, for a hamming distance of 0.

Sample Input 3

3
1 0 1
2
1 1
2 3

Sample Output 3

1

Sample Input 4

5
0 1 0 1 0
1
1 5

Sample Output 4

2

It may be optimal to perform no operation.

Sample Input 5

9
0 1 0 1 1 1 0 1 0
3
1 4
5 8
6 7

Sample Output 5

3

Sample Input 6

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

Sample Output 6

5

Sample Input 7

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

Sample Output 7

1

见题面 Input 部分

见题面 Output 部分