#include <bits/stdc++.h>
using namespace std;
int n, i;
double am, vm2, d, tant, ti, vm, t, s, daux, tfin;
int main() {
  scanf("%d %lf %lf", &n, &am, &d);
  tant = 0;
  for (i = 0; i < n; i++) {
    scanf("%lf %lf", &ti, &vm);
    t = (vm / am);
    s = 0.5 * (vm * vm / am);
    daux = d - s;
    if (daux < 0) {
      vm2 = sqrt(2 * d * am);
      tfin = vm2 / am;
      tfin += ti;
    } else {
      tfin = daux / vm;
      tfin += (ti + t);
    }
    if (tfin > tant) {
      tant = tfin;
    }
    printf("%.10lf\n", tant);
  }
  return 0;
}
