#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, d, v, t;
  scanf("%d%d%d", &n, &a, &d);
  double last = 0;
  for (int i = 1; i <= n; i++) {
    scanf("%d%d", &t, &v);
    double t1 = (double)v / a, t2;
    if (t1 > sqrt(2.0 * d / a)) {
      t1 = t + sqrt((double)2.0 * d / a);
    } else {
      t2 = ((double)d - 0.5 * a * t1 * t1) / v;
      t1 = t + t1 + t2;
    }
    if (t1 > last) last = t1;
    printf("%.10lf\n", last);
  }
  return 0;
}
