#include <bits/stdc++.h>
using namespace std;
int main() {
  float a, d, t, v, tp = -1, tt, l, time = 0;
  int i, n;
  scanf("%d%f%f", &n, &a, &d);
  for (i = 0; i < n; i++) {
    scanf("%f%f", &t, &v);
    tt = v / a;
    l = (tt * v) / 2;
    if (l >= d) {
      tt = sqrt(d / (a / 2));
      tt += t;
      if (time > tt) {
        tt = time;
      } else
        time = tt;
      printf("%f\n", tt);
    } else {
      tt += (d - l) / v;
      tt += t;
      if (time > tt) {
        tt = time;
      } else
        time = tt;
      printf("%f\n", tt);
    }
  }
  return 0;
}
