/****************************************\
* Author : ztx
* Title  : [bzoj] 3893: [Usaco2014 Dec]Cow Jog
[cogs] 1945. 奶牛跑步
* ALG    :
* CMT    : 水 
* Time   :
\****************************************/
 
#include <cstdio>
 
typedef long long ll ;
 
int CH , NEG ;
template <typename TP>
inline void read(TP& ret) {
    ret = NEG = 0 ; while (CH=getchar() , CH<'!') ;
    if (CH == '-') NEG = true , CH = getchar() ;
    while (ret = ret*10+CH-'0' , CH=getchar() , CH>'!') ;
    if (NEG) ret = -ret ;
}
 
#define  maxn  100010LL
 
ll n , m ;
ll p[maxn] , v[maxn] ;
int ans = 0 ;
 
int main() {
int i ;
    #define READ
    #ifdef  READ
        freopen("cowjoga.in" ,"r",stdin ) ;
        freopen("cowjoga.out","w",stdout) ;
    #endif
    read(n) , read(m) ;
    ans = n ;
    for (i = 1 ; i <= n ; i ++ )
        read(p[i]) , read(v[i]) ,
        p[i] += v[i]*m ;
    for (i = n ; i ; i -- ) {
        if (p[i] <= p[i-1]) ans -- , p[i-1] = p[i] ;
    }
    printf("%d\n", ans) ;
    #ifdef  READ
        fclose(stdin) ; fclose(stdout) ;
    #else
        getchar() ; getchar() ;
    #endif
    return 0 ;
}