#include<stdio.h>
int n,i,m,now;
long long t,p[100001];
char ch[3000000],*ptr=ch;
inline int getint(){
	static int ret;
	while(*ptr<48) ptr++;
	ret=*ptr++-48;
	while(*ptr>47) ret=ret*10+*ptr++-48;
	return ret;
}
int main(){
	freopen("cowjoga.in","r",stdin);
	freopen("cowjoga.out","w",stdout);
	fread(ch,1,3000000,stdin);
	n=getint(),t=getint();
	for(i=1;i<=n;i++) p[i]=getint(),p[i]+=t*getint();
	for(i=n;i>0;){
		now=i,m++;
		while(p[i]>=p[now]) i--;
	}
	printf("%d",m);
}