#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
using namespace std;
inline int read()
{
	char c=getchar();int x=0;bool f=0;
	for(;!isdigit(c);c=getchar())f^=!(c^45);
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	if(f)x=-x;return x;
}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 600005
#define inf 0x3f3f3f3f

int n[2],k;
vector<pii>s[2];
int f[maxn][2][2],res;

// 当前所在教室,另一个教室有没有看过 

vector<pii>::iterator get(int j,int x){
	return lower_bound(s[j].begin(),s[j].end(),mkp(x+1,0));
}

signed main()
{
	n[0]=read(),n[1]=read(),k=read();
	s[0].pb(mkp(-1,-1)),s[1]=s[0];
	For(o,0,1)For(i,1,n[o]){
		int l=read(),r=read()-1;
		s[o].pb(mkp(l,r));
	}
	For(o,0,1)sort(s[o].begin(),s[o].end());
	memset(f,63,sizeof f);
	bool qwq=s[0].size()&&s[0][0].fi==0;
	f[qwq][0][0]=0;
	For(i,0,n[0]+n[1]){
		For(j,0,1)For(t,0,1)if(f[i][j][t]<inf){
			res=i;
			int x=f[i][j][t];
		//	cout<<"i,j,t "<<i<<" "<<j<<" "<<t<<' '<<f[i][j][t]<<"\n"; 
			auto it=get(j,x);
			auto it1=--get(!j,x);
			if(it!=s[j].end()){
				auto it2=--get(!j,it->fi);
				bool same=it1==it2;
				f[i+1][j][t&same]=min(f[i+1][j][t&same],it->fi);
			}
			auto nxt=--get(!j,x+k);
			if((nxt==it1 && t) || (nxt->se<x+k)) ++nxt;
			if(nxt!=s[!j].end()){
		//		cout<<"it->fi "<<nxt->fi<<"\n";
				auto it2=get(j,max(nxt->fi,x+k));
				bool same=it2==it;
				f[i+1][!j][same]=min(f[i+1][!j][same],max(nxt->fi,x+k));
			}
		}
		if(res<i)break;
	}
	cout<<res;
	return 0;
}