#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, a, d;
  long long t, v;
  double prev = 0;
  scanf("%I64d%I64d%I64d", &n, &a, &d);
  for (int i = 1; i <= n; i++) {
    scanf("%I64d%I64d", &t, &v);
    double tt = sqrt((2 * d) / (a * 1.0));
    if (tt * a > v) {
      tt = v / (a * 1.0) + (d - v * v / (2 * a * 1.0)) / v;
    }
    tt += t;
    if (tt < prev) tt = prev;
    printf("%.8lf\n", tt);
    prev = tt;
  }
}
