#include <stdio.h>
#include <stdlib.h>
int multiplicare (int x, int y) {
    x=x*y;
    return x;
}
int main()
{
    FILE *fin=fopen("bile2.in", "r");
    FILE *fout=fopen("bile2.out", "w");
    int n, m, x, t, i, sj, fr, h1, hb;
    fscanf(fin, "%d%d", &n, &m);
    int h[n], k[n];
    for (i=0; i<n; i++) {
        fscanf (fin, "%d%d", &h[i], &k[i]);
    }
    for (i=0; i<m; i++) {
        fscanf (fin, "%d%d", &x, &t);
        sj=0; //0=cade, 1=sare
        h1=h[x-1];
        fr=1;
        while (t) {
            if (sj==0) {
                t=t-h1;
                h1=0;
            }
            if (sj==1) {
                t=t-h[x-1]+k[x-1]*fr;
                h1=h[x-1]-k[x-1]*fr;
                fr++;
            }
            if (sj) {sj--;} else sj++;
        }
        fprintf (fout, "%d\n", h1);
    }
    fclose(fin);
    fclose(fout);
    return 0;
}