#include <bits/stdc++.h>
int main() {
  long n, a, d, t, v;
  scanf("%i %i %i\n", &n, &a, &d);
  double _t_prev = 0.0;
  double _d = d;
  double _a = a;
  for (int i = 0; i < n; ++i) {
    scanf("%i %i\n", &t, &v);
    double _v = v;
    double _t = t;
    double _t_min = sqrt(_d * 2.0 / _a);
    double _v_max = _a * _t_min;
    if (_v_max <= _v) {
      if (_t_min + _t > _t_prev) _t_prev = _t_min + _t;
    } else {
      double _t_acc = _v / _a;
      double _s_acc = _a * _t_acc * _t_acc / 2.0;
      double _s_rem = _d - _s_acc;
      double _t_rem = _s_rem / _v;
      double _t_sum = _t_acc + _t_rem + _t;
      if (_t_sum > _t_prev) _t_prev = _t_sum;
    }
    printf("%.15f\n", _t_prev);
  }
  return 0;
}
