#include <bits/stdc++.h>
using namespace std;
#define SZ 200077
typedef pair<int,int> pii;
#define fi first
#define se second
#define pb push_back
typedef long long ll;
#define lg lg__
pii lg[SZ];
int n,d,L,sm[SZ];
const int S=400;
vector<int> g[SZ],GT;
#define all(s) s.begin(),s.end()
int qs[SZ],pf[SZ],ms[SZ];
#define sz(s) (int)(s).size()
ll ans=0;
void large(int x) {
    auto&G=g[x];
    for(int i=0;i<=L;++i) qs[i]=0;
    for(int j=0;j<G.size();++j) {
        ++qs[G[j]];
        --qs[min(G[j]+(j+1)*20,L+1)];
    }
    for(int i=1;i<=L;++i) if(i>=20) qs[i]+=qs[i-20];
    static int anx[SZ],cge[SZ];
    anx[L+1]=L+1; cge[L+1]=0;
    for(int i=L;i>=0;--i) cge[i]=0;
    for(int i=L;i>=0;--i)
        if(qs[i]) anx[i]=i;
        else anx[i]=anx[i+1];
    for(int i:GT) if(i!=x) ++cge[sm[i]];
    for(int i=L;i>=0;--i) cge[i]+=cge[i+1];
    for(int i:GT) if(i!=x) {
        int nx;
        if(lg[i].se==1) {
            nx=anx[lg[i].fi];
        }
        else {
            if(ms[x]>=lg[i].fi) nx=0;
            else nx=anx[0];
        }
        ans+=cge[nx];
        ans-=sm[i]>=nx;
    }
}
const int B=500;
int bsum[SZ],bpref[SZ];
void edt(int x,int y) {
    int b=x/B;
    for(int j=b;j<=L/B;++j) bsum[j]+=y;
    for(int j=x;j/B==b;++j) bpref[j]+=y;
}
int qry(int x) {
    if(x<0) return 0;
    int ans=bpref[x];
    if(x/B) ans+=bsum[x/B-1];
    return ans;
}
int main() {
    scanf("%d%d%d",&n,&d,&L); L+=61;
    for(int i=1;i<=n;++i) {
        int x,y;
        scanf("%d%d",&x,&y);
        g[x].push_back(y);
    }
    for(int i=1;i<=d;++i) if(g[i].size()) GT.push_back(i);
    for(int i:GT) {
        sort(all(g[i]));
        if(g[i].size()>=3) lg[i]=pii(0,2);
        else if(g[i].size()>=2) lg[i]=pii(g[i][0]+g[i][1],2);
        else lg[i]=pii(g[i][0],1);
        sm[i]=min(g[i].back()+(sz(g[i])-1)*20,L);
    }
    static int cntworse[SZ],cntbetter[SZ*3];
    static vector<pii> event[SZ*3],ei[SZ*3];
    for(int i:GT) {
        int ss = lg[i].fi+(lg[i].se==1)*(L*2);
        ei[ss].pb(pii(i,i));
        cntworse[sm[i]]++,cntbetter[ss]++;
    }
    // suffix sum on cntworse and prefix on cntbetter
    for(int i=1;i<=L;++i) cntworse[i]+=cntworse[i-1];
    for(int i=L*3;i>=0;--i) cntbetter[i]+=cntbetter[i+1];
    for(int i:GT) {
        auto&G=g[i];
        if(G.size()<2) ms[i]=-1;
        else {
            ms[i]=G.back()+G[sz(G)-2]+20*(sz(G)-2);
            ms[i]=min(ms[i],L+L);
        }
        if(0) {
            large(i);
            continue;
        }
        vector<int> S;
        for(int u=0;u<sz(G);++u) {
            for(int z=0;z<=u&&G[u]+20*z<=L;++z) {
                S.push_back(G[u]+20*z);
            }
        }
        sort(all(S));reverse(all(S));
        ll last_cnt_worse=0;
        int prev=L+1;
        for(int t:S) {
            ll cnt_better = cntbetter[t+L*2]-1;
            ll cnt_worse = cntworse[t]-1;
            ans += cnt_better * (cnt_worse - last_cnt_worse);
            last_cnt_worse = cnt_worse;
            event[t+L*2].push_back(pii(t, prev-1));
            prev = t;
        }
        if(ms[i]!=-1)
        {
            ll cnt_better = cntbetter[ms[i]]-1;
            ll cnt_worse = n-1;
            ans += cnt_better * (cnt_worse - last_cnt_worse);
            event[ms[i]].push_back(pii(0, prev-1));
        }
    }
    for(int i=L*3;i>=0;--i) {
        for(auto p:ei[i]) {
            int x=p.fi,y=p.se;
            edt(y,1);
        }
        for(auto p:event[i]) {
            int x=p.fi,y=p.se;
            ans+=qry(y)-qry(x-1);
        }
    }
    cout<<ans<<"\n";
}