#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();
#define RD(v) int v=0;{int _c;while(_c=*rp++-48,_c>=0)v=v*10+_c;}

#define WTHI(v) {long _z=v,_n=0,_d=0;while(++_n,_d=_d<<8|0x30|_z%10,_z/=10);*(long*)wp=_d;wp+=_n;}
#define WTLO(v) {long _z=v,_n=8,_d=0;while(_d=_d<<8|0x30|_z%10,_z/=10,--_n);*(long*)wp=_d;wp+=8;}
#define WT(v) if(v>=100000000){WTHI(v/100000000);WTLO(v);}else{WTHI(v);}

#define MD 1000000007

struct { int l,r; } lr[3000];
long c[3002],d[3002];

main(){
	char*rp=mmap(0l,5l*6004,1,2,0,0ll);
	RD(n);
	RD(m);
	RD(k);
	for(int i=0;i<m;++i){
		RD(l);
		lr[i].l=l-1;
		RD(r);
		lr[i].r=r;
	}
	c[1]=1;
	while(k--){
		{
			long t=0;
			for(int i=0;i<3000;++i){
				c[i+1]=t+=c[i+1];
			}
		}
		for(int i=0;i<m;++i){
			int l=lr[i].l;
			int r=lr[i].r;
			long s=c[r]-c[l];
			d[l]+=s;
			d[r]-=s;
		}
		{
			long t=0;
			for(int i=0;i<3000;++i){
				t+=d[i];
				c[i+1]=t%MD;
				d[i]=0;
			}
		}
	}
	char wbuf[16],*wp=wbuf;
	WT(c[n]);
	write(1,wbuf,wp-wbuf);
	_exit(0);
}