#include <stdio.h>
 
int main(void) {
int t,s;
scanf("%d",&t); scanf("%ld", &s);
int i,j;
long int moments[s],cookingtime[s],comparison[s];
for(i=0;i<t;i++) {
	for(j=0;j<1;j++) {
		scanf("%ld", &moments[j]); 
		comparison[j]=moments[j];
		scanf("%ld",&cookingtime[j]); }
    for(j=1;j<s;j++) {
    	scanf("%ld", &moments[j]); 
    	comparison[j]=(moments[j]-moments[j-1]);
    	scanf("%ld",&cookingtime[j]); }
    	long int count=0;
for(j=0;j<s;j++) {
	if(comparison[j]>=cookingtime[j]) { count++; }
}
	printf("%ld \n",count);
}	
	return 0;
}		
 
 
 
 
 

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