#include <bits/stdc++.h>
double ans, temp, ov;
int n, a, d, t, v, i;
int main() {
  scanf("%d%d%d", &n, &a, &d);
  while (n--) {
    scanf("%d%d", &t, &v);
    ov = v * .5 * v / a;
    temp = ov > d ? t + sqrt(d * 2. / a) : t + d * 1. / v + v * .5 / a;
    if (ans > temp) temp = ans;
    printf("%.9f\n", ans = temp);
  }
  return 0;
}
