run

#include <bits/stdc++.h>
#define Nmax 100001
using namespace std;
unsigned long long int a[Nmax],Suf[Nmax],S[Nmax],G[Nmax];

int main()
{
    int n,m,k;
    ifstream f("run.in");
    f>>n>>m>>k;
    for(int i=1;i<=n;++i)
        f>>a[i];
    unsigned long long int SUM=0,SUM1=0;
    for(int i=n;i>=1;--i) /// suf[i]=a[i]+a[i+1]+...+a[N] si s[i]=(N-i+1)*a[i]+(N-(i+1)+1)*a[i+1]+...+1*a[N]
        SUM+=a[i],Suf[i]=SUM,SUM1+=(1ULL*n-1ULL*i+1)*a[i],S[i]=SUM1;
    int s,d;
    for(int i=0;i<m;++i)
        f>>s>>d,G[i]=S[s]-S[d+1]-(1ULL*n-1ULL*d)*(Suf[s]-Suf[d+1]);
    sort(G,G+m);
    unsigned long long int GO=0;
    for(int i=0;i<k;++i)
        GO+=G[i];
    ofstream g("run.out");
    g<<GO<<'\n';
    return 0;
}