Graffiti

#include <fstream>
using namespace std;
const int N=1e5;
const int Log=17;
long long S[N+1];
int rmq[Log+1][N+1],lg2[N+1];
int main()
{
    int n,m,L,x,y;
    ifstream fin("graffiti.in");
    fin>>n;
    for(int i=1;i<=n;++i)
        fin>>L>>rmq[0][i],S[i]=S[i-1]+L;
    for(int i=2;i<=n;++i)
        lg2[i]=lg2[i>>1]+1;
    for(int i=1;i<=Log;++i)
        for(int j=1;j+(1<<(i-1))-1<=n;++j)
            rmq[i][j]=min(rmq[i-1][j],rmq[i-1][j+(1<<(i-1))]);
    fin>>m;
    ofstream fout("graffiti.out");
    while(m--)
    {
        fin>>x>>y;
        int l_lg=lg2[y-x+1];
        fout<<(S[y]-S[x-1])*min(rmq[l_lg][x],rmq[l_lg][y-(1<<l_lg)+1])<<'\n';
    }
    return 0;
}