Problem: 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

Solution (in CPP):

Solution:
#include<set>
#include<map>
#include<deque>
#include<queue>
#include<stack>
#include<cmath>
#include<ctime>
#include<bitset>
#include<string>
#include<vector>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<climits>
#include<complex>
#include<iostream>
#include<algorithm>
#define ll long long
#define inf 1e9
using namespace std;

inline void up(int &x,const int &y){if(x<y)x=y;}
const int maxn = 210000;

int n,m;
int b[maxn],s[maxn],f[maxn];
vector<int>V[maxn];

int segf[maxn<<2],segd[maxn<<2];
void pushup(int seg[],const int x){ seg[x]=seg[x<<1]>seg[x<<1|1]?seg[x<<1]:seg[x<<1|1]; }
void build(const int x,const int l,const int r)
{
	if(l==r) { segd[x]=l>=0?-inf:0; return; }
	int mid=l+r>>1,lc=x<<1,rc=lc|1;
	build(lc,l,mid); build(rc,mid+1,r);
	pushup(segd,x);
}
int lx,rx,loc,c;
void upd(int seg[],const int x,const int l,const int r)
{
	if(l==r) { seg[x]=c; return; }
	int mid=l+r>>1,lc=x<<1,rc=lc|1;
	if(loc<=mid) upd(seg,lc,l,mid);
	else upd(seg,rc,mid+1,r);
	pushup(seg,x);
}
int query(int seg[],const int x,const int l,const int r)
{
	if(rx<l||r<lx) return -inf;
	if(lx<=l&&r<=rx) return seg[x];
	int mid=l+r>>1,lc=x<<1,rc=lc|1;
	return max(query(seg,lc,l,mid),query(seg,rc,mid+1,r));
}
int re;

int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",&b[i]),re+=!b[i];
	for(int i=1;i<=n;i++) s[i]=s[i-1]+(b[i]?1:-1);
	build(1,0,n);
	for(int i=1;i<=n;i++) f[i]=-inf;
	
	scanf("%d",&m);
	for(int i=1;i<=m;i++)
	{
		int l,r; scanf("%d%d",&l,&r);
		V[l].push_back(r);
	}
	for(int i=1;i<=n;i++)
	{
		for(int j=0;j<V[i].size();j++)
		{
			int r=V[i][j];
			lx=0,rx=i-1; int cc=query(segf,1,0,n);
			up(f[r],cc+s[r]-s[i-1]);
			
			lx=i-1,rx=r-1; cc=query(segd,1,0,n);
			up(f[r],cc+s[r]);
			
			loc=r,c=f[r];
			upd(segf,1,0,n);
			c=f[r]-s[r]; upd(segd,1,0,n);
		}
	}
	int ans=0;for(int i=1;i<=n;i++) up(ans,f[i]);
	printf("%d\n",n-(re+ans));
	
	return 0;
}