/*{{{*/
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<string>
#include<iostream>
#include<sstream>
#include<set>
#include<map>
#include<queue>
#include<bitset>
#include<vector>
#include<limits.h>
#include<assert.h>
#define SZ(X) ((int)(X).size())
#define ALL(X) (X).begin(), (X).end()
#define REP(I, N) for (int I = 0; I < (N); ++I)
#define REPP(I, A, B) for (int I = (A); I < (B); ++I)
#define FOR(I, A, B) for (int I = (A); I <= (B); ++I)
#define FORS(I, S) for (int I = 0; S[I]; ++I)
#define RS(X) scanf("%s", (X))
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define GET_POS(c,x) (lower_bound(c.begin(),c.end(),x)-c.begin())
#define CASET int ___T; scanf("%d", &___T); for(int cs=1;cs<=___T;cs++)
#define MP make_pair
#define PB push_back
#define MS0(X) memset((X), 0, sizeof((X)))
#define MS1(X) memset((X), -1, sizeof((X)))
#define LEN(X) strlen(X)
#define F first
#define S second
using namespace std;
typedef int64_t LL;
typedef uint64_t ULL;
typedef long double LD;
typedef pair<int,int> PII;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<PII> VPII;
typedef pair<LL,LL> PLL;
typedef vector<PLL> VPLL;
template<class T> void _R(T &x) { cin >> x; }
void _R(int &x) { scanf("%d", &x); }
void _R(int64_t &x) { scanf("%lld", &x); }
void _R(double &x) { scanf("%lf", &x); }
void _R(char &x) { scanf(" %c", &x); }
void _R(char *x) { scanf("%s", x); }
void R() {}
template<class T, class... U> void R(T &head, U &... tail) { _R(head); R(tail...); }
template<class T> void _W(const T &x) { cout << x; }
void _W(const int &x) { printf("%d", x); }
void _W(const int64_t &x) { printf("%lld", x); }
void _W(const double &x) { printf("%.16f", x); }
void _W(const char &x) { putchar(x); }
void _W(const char *x) { printf("%s", x); }
template<class T> void _W(const vector<T> &x) { for (auto i = x.begin(); i != x.end(); _W(*i++)) if (i != x.cbegin()) putchar(' '); }
void W() {}
template<class T, class... U> void W(const T &head, const U &... tail) { _W(head); putchar(sizeof...(tail) ? ' ' : '\n'); W(tail...); }
template<class T, class... U> void DEBUG(const T &head, const U &... tail) { 
#ifdef HOME
    _W('#'); _W(head); putchar(sizeof...(tail) ? ' ' : '\n'); W(tail...);
#endif
}
int MOD = 1e9+7;
void ADD(LL& x,LL v){x=(x+v)%MOD;if(x<0)x+=MOD;}
/*}}}*/
const int SIZE = 1e6+10;
int mi[SIZE],_tmp[SIZE];
void push(int id){
    mi[id*2]=min(_tmp[id],mi[id*2]);
    mi[id*2+1]=min(_tmp[id],mi[id*2+1]);
    _tmp[id*2]=min(_tmp[id],_tmp[id*2]);
    _tmp[id*2+1]=min(_tmp[id],_tmp[id*2+1]);
    _tmp[id]=INT_MAX;
}
void pull(int id){
    mi[id]=min(mi[id*2],mi[id*2+1]);
}
LL qq(int L,int R,int id,int ll,int rr){
    if(R<ll||L>rr)return INT_MAX;
    if(L>=ll&&R<=rr)return mi[id];
    int mm=(L+R)/2;
    push(id);
    return min(qq(L,mm,id*2,ll,rr),qq(mm+1,R,id*2+1,ll,rr));
}
void ins(int L,int R,int id,int ll,int rr,int v){
    if(R<ll||L>rr)return;
    if(L>=ll&&R<=rr){
        mi[id]=min(mi[id],v);
        _tmp[id]=min(_tmp[id],v);
        return;
    }
    int mm=(L+R)/2;
    push(id);
    ins(L,mm,id*2,ll,rr,v);
    ins(mm+1,R,id*2+1,ll,rr,v);
    pull(id);
}
int dp[SIZE],N,b[SIZE],Q,cb[SIZE];
VI lef[SIZE];
int main(){
    REP(i,SIZE)mi[i]=1e9,_tmp[i]=1e9;
    R(N);
    FOR(i,1,N){
        R(b[i]);
        cb[i]=b[i]+cb[i-1];
    }
    R(Q);
    REP(i,Q){
        int x,y;
        R(x,y);
        lef[y].PB(x);
    }
    auto mii = [](auto& x,auto y){if(x>y)x=y;};
    FOR(i,1,N){
        dp[i]=dp[i-1]+b[i];
        DEBUG("dp_pre[",i,"]",dp[i]);
        REP(j,SZ(lef[i])){
            int y=lef[i][j];
            mii(dp[i],dp[y-1]+(i-y+1)-(cb[i]-cb[y-1]));
            int tmp=qq(0,N+1,1,y,y);
            mii(dp[i],tmp+i-cb[i]);
            ins(0,N+1,1,y,i+1,min(tmp,dp[y-1]-(y-1)+cb[y-1]));
        }
    }
    W(dp[N]);
    return 0;
}


Measured memory_bytes: 41856