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 <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------

template<class V,int NV> class SegTree_1 {
public:
	vector<V> val;
	static V const def=1<<20;
	V comp(V l,V r){ return min(l,r);};
	
	SegTree_1(){val=vector<V>(NV*2,def);};
	V getval(int x,int y,int l=0,int r=NV,int k=1) { // x<=i<y
		if(r<=x || y<=l) return def;
		if(x<=l && r<=y) return val[k];
		return comp(getval(x,y,l,(l+r)/2,k*2),getval(x,y,(l+r)/2,r,k*2+1));
	}
	void update(int entry, V v) {
		entry += NV;
		val[entry]=v;
		while(entry>1) entry>>=1, val[entry]=comp(val[entry*2],val[entry*2+1]);
	}
};
SegTree_1<int,1<<20> st;

int N;
int S[202020];
int Q;
vector<int> ev[202020];
int dp[202020];


void solve() {
	int i,j,k,r,x,y; string s;
	
	cin>>N;
	FOR(i,N) {
		cin>>x;
		dp[0]+=x;
		if(x==1) S[i+1]=S[i]-1;
		else S[i+1]=S[i]+1;
	}
	
	
	FOR(i,N+1) {
		if(i) dp[i]=1<<20;
		st.update(i,dp[i]+(S[N]-S[i]));
	}
	
	cin>>Q;
	FOR(i,Q) {
		cin>>x>>y;
		ev[x].push_back(y);
	}
	for(i=1;i<=N;i++) {
		FORR(r,ev[i]) {
			x = min(dp[i-1]+(S[r]-S[i-1]),st.getval(i,r+1) - (S[N]-S[r]));
			if(x<dp[r]) {
				dp[r]=x;
				st.update(r,dp[r]+(S[N]-S[r]));
			}
		}
		dp[i]=min(dp[i],dp[i-1]);
		
	}
	cout<<*min_element(dp,dp+N+1)<<endl;
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}