15A - Cottage Village - CodeForces Solution

n,width=map(int,input().split())
a=[]
for i in range(n):
    pos,w=map(int,input().split())
    a.append(pos-w/2)
    a.append(pos+w/2)
a.sort()
s=2
for i in range(1,2*n-1,2):
    if a[i+1]-a[i]>width:
        s+=2
    elif a[i+1]-a[i]==width:
        s+=1
print(s)