#include <bits/stdc++.h>
using namespace std;
int t1;
double aa, d;
int check(double x, double v) {
  if (x <= v / aa) {
    double ha = aa * x;
    return ha * x >= d * 2.0;
  } else {
    double t = v / aa, la = x - t;
    return t * v >= (d - la * v) * 2;
  }
}
int main() {
  double mn, mx = -1, t, v, l, r, mid, now, eps = 1e-11;
  scanf("%d%lf%lf", &t1, &aa, &d);
  mx = -1;
  while (t1--) {
    scanf("%lf%lf", &t, &v);
    l = 0;
    r = 1e8;
    mn = r;
    while (r - l > eps) {
      mid = (l + r) / 2.0;
      if (check(mid, v)) {
        mn = min(mn, mid);
        r = mid;
      } else
        l = mid;
    }
    now = mn + t;
    if (now > mx + eps) {
      printf("%.13lf\n", now);
      mx = now;
    } else
      printf("%.13lf\n", mx);
  }
}
