#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> P;
#define F first
#define S second
#define INF 1<<19
struct SEG{
	int seg[1<<19];
	SEG(void){for(int i=0;i<1<<19;i++)seg[i]=INF;}
	void up(int a,int x){
		a+=(1<<18)-1;
		seg[a]=min(seg[a],x);
		while(a>0){
			a=(a-1)/2;
			seg[a]=min(seg[a*2+1],seg[a*2+2]);
		}
	}
	int que(int a,int b,int l,int r,int k){
		if(r<a||b<l)return INF;
		if(a<=l&&r<=b)return seg[k];
		return min(que(a,b,l,(l+r-1)/2,k*2+1),que(a,b,(l+r+1)/2,r,k*2+2));
	}
};
int n,q,s[1<<18],l,r,a,o,dp[1<<18],d=INF,e;
P x[1<<18];
SEG p;
int main(void){
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
		scanf("%d",&a);
		if(a)s[i]--;
		else s[i]++;
		s[i]+=s[i-1];
		dp[i]=INF;
	}
	scanf("%d",&q);
	for(int i=0;i<q;i++)scanf("%d%d",&x[i].F,&x[i].S);
	sort(x,x+q);
	p.up(0,(n-s[n])/2);
	dp[0]=(n-s[n])/2;
	for(int i=0;i<q;i++){
		l=x[i].F,r=x[i].S;
		while(e<l)d=min(d,dp[e++]);
		o=min(d+s[r]-s[l-1],s[r]+p.que(l,r,0,(1<<18)-1,0));
		p.up(r,o-s[r]);
		dp[r]=o;
	}
	while(e<=n)d=min(d,dp[e++]);
	printf("%d\n",d);
}
