import core.bitop;
import std.algorithm;
import std.ascii;
import std.bigint;
import std.conv;
import std.functional;
import std.math;
import std.numeric;
import std.range;
import std.stdio;
import std.string;
import std.random;
import std.typecons;
import std.container;

alias sread = () => readln.chomp();
alias Point2 = Tuple!(long, "y", long, "x");

T lread(T = long)()
{
    return readln.chomp.to!T();
}

T[] aryread(T = long)()
{
    return readln.split.to!(T[])();
}

void scan(TList...)(ref TList Args)
{
    auto line = readln.split();
    foreach (i, T; TList)
    {
        T val = line[i].to!(T);
        Args[i] = val;
    }
}

void main()
{
    long n, h, w;
    scan(n, h, w);
    long[] len = new long[n];
    long[] side = new long[n];
    long[] ans = new long[n];
    foreach (e; 0 .. n)
    {
        scan(len[e], side[e]);
    }
    foreach (ref e; len)
    {
        if (e < h)
        {
            e = 0;
        }
    }
    foreach (ref e; side)
    {
        if (e < w)
        {
            e = 0;
        }
    }
    foreach (i, ref e; ans)
    {
        e = len[i] && side[i];
    }
    ans.sum.writeln();
}