#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, d;
  cin >> n >> a >> d;
  double prevTime = 0;
  for (int i = 0; i < n; i++) {
    int t, v;
    cin >> t >> v;
    double tm = (v + 0.0) / a;
    double dist = 0.5 * a * tm * tm;
    if (dist >= d) {
      tm = sqrt(2.0 * d / a);
    } else {
      tm += (d - dist) / v;
    }
    tm += t;
    tm = max(prevTime, tm);
    printf("%.8f\n", tm);
    prevTime = max(prevTime, tm);
  }
  return 0;
}
