#include <bits/stdc++.h>
using namespace std;
const int mod = (int)(1e9) + 7;
const int N = 200005;
int n;
double fnd(double cur_time, double v, double a, double d) {
  if (v * v >= 2 * a * d) {
    return sqrt(2 * d / a) + cur_time;
  } else {
    return d / v + v / (2 * a) + cur_time;
  }
}
int a, d;
double mx_t;
int ti, v;
int main() {
  scanf("%d %d %d", &n, &a, &d);
  for (int i = 0; i < n; ++i) {
    scanf("%d %d", &ti, &v);
    mx_t = max(mx_t, fnd(ti, v, a, d));
    printf("%.6f\n", (double)mx_t);
  }
  return 0;
}
