#include <bits/stdc++.h>
using namespace std;
double n, a, d, last;
int main() {
  cin >> n >> a >> d;
  cout << fixed << setprecision(5);
  for (int i = 0; i < n; i++) {
    int v0, t0;
    double ans, v, t;
    scanf("%d %d", &t0, &v0);
    v = v0;
    t = t0;
    if (v * v > 2 * a * d)
      ans = t + sqrt(2 * d / a);
    else
      ans = t + (2 * a * d + v * v) / (2 * a * v);
    ans = max(ans, last);
    cout << ans << endl;
    last = ans;
  }
}
