/* Headers */
#include <unordered_map>
#include <algorithm>
#include <iostream>
#include <cstring>
#include <climits>
#include <cstdio>
#include <cctype>
#include <vector>
#include <cmath>
#include <queue>
#include <stack>
#include <set>
#define FOR(i,a,b,c) for(int i=(a);i<=(b);i+=(c))
#define ROF(i,a,b,c) for(int i=(a);i>=(b);i-=(c))
#define FORL(i,a,b,c) for(long long i=(a);i<=(b);i+=(c))
#define ROFL(i,a,b,c) for(long long i=(a);i>=(b);i-=(c))
#define FORR(i,a,b,c) for(register int i=(a);i<=(b);i+=(c))
#define ROFR(i,a,b,c) for(register int i=(a);i>=(b);i-=(c))
#define RevEdge(x) x^1
#define lowbit(x) x&(-x)
#define LeftChild(x) x<<1
#define RightChild(x) (x<<1)+1
#define CLOSE_IN() fclose(stdin);
#define CLOSE_OUT() fclose(stdout);
#define FILE_IN(x) freopen(x,"r",stdin);
#define FILE_OUT(x) freopen(x,"w",stdout);
#define IOS(x) std::ios::sync_with_stdio(x)
#define Dividing() printf("-----------------------------------\n");
namespace FastIO {
#define gc() (iS == iT ? (iT = (iS = ibuff) + fread(ibuff, 1, SIZ, stdin), (iS == iT ? EOF : *iS++)) : *iS++)
    const int SIZ = 1 << 21 | 1;
    char* iS, * iT, ibuff[SIZ], obuff[SIZ], * oS = obuff, * oT = oS + SIZ - 1, fu[110], cc;
    int fr;
    inline void out() {
        fwrite(obuff, 1, oS - obuff, stdout);
        oS = obuff;
    }
    template<class Type>
    inline void read(Type& x) {
        x = 0;
        Type y = 1;
        for (cc = gc(); (cc > '9' || cc < '0') && cc != '-'; cc = gc());
        cc == '-' ? y = -1 : x = (cc & 15);
        for (cc = gc(); cc >= '0' && cc <= '9'; cc = gc())
            x = x * 10 + (cc & 15);
        x *= y;
    }
    template<class Type>
    inline void print(Type x, char text = '\n') {
        if (x < 0)
            * oS++ = '-', x *= -1;
        if (x == 0)
            * oS++ = '0';
        while (x)
            fu[++fr] = x % 10 + '0', x /= 10;
        while (fr);
            * oS++ = fu[fr--];
        * oS++ = text;
        out();
    }
    inline void prints(char x[], char text = '\n') {
        for (register int i = 0; x[i]; ++i)
            * oS++ = x[i];
        * oS++ = text;
        out();
    }
}
using namespace FastIO;
template<typename T>
inline T max(T a, T b) {return (a > b) ? a : b;}
template<typename T>
inline T min(T a, T b) {return (a > b) ? b : a;}
/* definitions */
const int MAXN = 1e6 + 10, mod = 1e9 + 7;
int n, A, B, gss;
int fac[MAXN], inv[MAXN], c[MAXN], w[MAXN], minx[MAXN], gs[MAXN];
/* functions */
inline int quick_power(int a, int b, int p = mod) {
    int res = 1, base = a;
    while(b) {
        if(b & 1) res = 1ll * base * res % p;
        b >>= 1; base = 1ll * base * base % p;
    } return res;
}
inline int binom(int n, int m) {
    if(!n) return 1;
    if(m < n) return 0;
    return 1ll * fac[m] * inv[m - n] % mod * inv[n] % mod;
}
int main(int argc, char *argv[]) {
    /*FILE_IN("data.in");*/ read(n); read(A); read(B);
    memset(minx, 0x3f, sizeof minx);
    FOR(i, 1, n, 1) {
        read(c[i]); read(w[i]);
        minx[c[i]] = min(minx[c[i]], w[i]);
    } int minf = 0, mins = 0;
    FOR(i, 1, n, 1) {
        if(minx[i] < minx[minf]) mins = minf, minf = i;
        else if(minx[i] < minx[mins]) mins = i;
    }
    FOR(i, 1, n, 1) {
        if(minx[c[i]] + w[i] <= A) w[i] = minx[c[i]];
        if(c[i] == minf && minx[mins] + w[i] <= B) gs[c[i]]++, gss++;
        if(c[i] != minf && minx[minf] + w[i] <= B) gs[c[i]]++, gss++;
    } int ans = 1; fac[0] = 1;
    FOR(i, 1, n, 1) fac[i] = 1ll * i * fac[i - 1] % mod;
    inv[n] = quick_power(fac[n], mod - 2);
    ROF(i, n - 1, 0, 1) inv[i] = 1ll * inv[i + 1] * (i + 1) % mod;
    FOR(i, 1, n, 1) {
        if(gs[i]) {
            ans = 1ll * ans * binom(gs[i], gss) % mod;
            gss -= gs[i];
        }
    } printf("%d\n", ans);
    return 0;
}


Measured memory_bytes: 13660