#include <bits/stdc++.h>
int main() {
  int n, a, d;
  int t, v;
  while (~scanf("%d%d%d", &n, &a, &d)) {
    double flag = -1;
    for (int i = 0; i < n; i++) {
      scanf("%d%d", &t, &v);
      double tt = sqrt(2.0 * d / double(a));
      if (a * tt > v) {
        tt = (1.0 * v) / a;
        tt += (d - a * tt * tt * 0.5) / v;
      }
      tt += t;
      if (tt < flag) tt = flag;
      printf("%.8lf\n", tt);
      flag = tt;
    }
  }
  return 0;
}
