import sys, os, io
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline
n, l, a = map(int, input().split())
x = 0
ans = 0
for _ in range(n):
t, l0 = map(int, input().split())
ans += (t - x) // a
x = t + l0
ans += (l - x) // a
print(ans)#include <bits/stdc++.h>
#define int long long
using namespace std;
signed main()
{
int n,brdu,wd;
cin >> n>>wd>>brdu;
int rn=0,br=0;
for(int i=0; i<n ;i++){
int x, y;
cin>> x>>y;
int msh=x-rn;
br+=msh/brdu;
rn=x+y;
}
int msh=wd-rn;
br+=msh/brdu;
cout<<br<<endl;
return 0;
}
1002. Find Common Characters | 1602A - Two Subsequences |
1555A - PizzaForces | 1607B - Odd Grasshopper |
1084A - The Fair Nut and Elevator | 1440B - Sum of Medians |
1032A - Kitchen Utensils | 1501B - Napoleon Cake |
1584B - Coloring Rectangles | 1562B - Scenes From a Memory |
1521A - Nastia and Nearly Good Numbers | 208. Implement Trie |
1605B - Reverse Sort | 1607C - Minimum Extraction |
1604B - XOR Specia-LIS-t | 1606B - Update Files |
1598B - Groups | 1602B - Divine Array |
1594B - Special Numbers | 1614A - Divan and a Store |
2085. Count Common Words With One Occurrence | 2089. Find Target Indices After Sorting Array |
2090. K Radius Subarray Averages | 2091. Removing Minimum and Maximum From Array |
6. Zigzag Conversion | 1612B - Special Permutation |
1481. Least Number of Unique Integers after K Removals | 1035. Uncrossed Lines |
328. Odd Even Linked List | 1219. Path with Maximum Gold |