1 #include <cstdio>  2 #include <cstdlib>  3 #include <cstring>  4 #include <climits>  5 #include <cctype>  6 #include <cmath>  7 #include <string>  8 #include <sstream>  9 #include <iostream> 10 #include <algorithm> 11 #include <iomanip> 12 using namespace std; 13 #include <queue> 14 #include <stack> 15 #include <vector> 16 #include <deque> 17 #include <set> 18 #include <map> 19 typedef long long LL; 20 typedef long double LD; 21 #define pi acos(-1.0) 22 #define lson l, m, rt<<1 23 #define rson m+1, r, rt<<1|1 24 typedef pair<int, int> PI; 25 typedef pair<int, PI> PP; 26 #ifdef _WIN32 27 #define LLD "%I64d" 28 #else 29 #define LLD "%lld" 30 #endif 31 //#pragma comment(linker, "/STACK:1024000000,1024000000") 32 //LL quick(LL a, LL b){LL ans=1;while(b){if(b & 1)ans*=a;a=a*a;b>>=1;}return ans;} 33 //inline int read(){char ch=‘ ‘;int ans=0;while(ch<‘0‘ || ch>‘9‘)ch=getchar();while(ch<=‘9‘ && ch>=‘0‘){ans=ans*10+ch-‘0‘;ch=getchar();}return ans;} 34 //inline void print(LL x){printf(LLD, x);puts("");} 35 //inline void read(double &x){char c = getchar();while(c < ‘0‘) c = getchar();x = c - ‘0‘; c = getchar();while(c >= ‘0‘){x = x * 10 + (c - ‘0‘); c = getchar();}} 36  37 const int maxn = 100005; 38 int X[maxn<<3]; 39 struct Seg 40 { 41     int h , l , r, s; 42     Seg() {} 43     Seg(int a,int b,int c,int d) : l(a) , r(b) , h(c) , s(d) {} 44     bool operator < (const Seg &cmp) const 45     { 46         return h < cmp.h; 47     } 48 } ss[maxn<<3]; 49 int len[maxn<<3],cnt[maxn<<3]; 50 void PushUp(int rt) 51 { 52     len[rt]=max(len[rt<<1], len[rt<<1|1]); 53 } 54 void PushDown(int rt) 55 { 56     if(cnt[rt]) 57     { 58         cnt[rt<<1]+=cnt[rt]; 59         cnt[rt<<1|1]+=cnt[rt]; 60         len[rt<<1]+=cnt[rt]; 61         len[rt<<1|1]+=cnt[rt]; 62         cnt[rt]=0; 63     } 64 } 65 void Update(int L, int R, int c, int l , int r, int rt) 66 { 67     if(L<=l && r<=R) 68     { 69         cnt[rt]+=c; 70         len[rt]+=c; 71         return ; 72     } 73 //    PushDown(rt); 74     int m=(l+r)>>1; 75     if(L<=m) 76         Update(L, R, c, lson); 77     if(m<R) 78         Update(L, R, c, rson); 79 //    PushUp(rt); 80     len[rt]=max(len[rt<<1], len[rt<<1|1])+cnt[rt]; 81 } 82 int main() 83 { 84 #ifndef ONLINE_JUDGE 85     freopen("in.txt", "r", stdin); 86     freopen("out.txt", "w", stdout); 87 #endif 88     int n; 89     while(~scanf("%d", &n)) 90     { 91         if(n<0) 92             break; 93         int w, h; 94         scanf("%d%d", &w, &h); 95         int m=0; 96         while(n--) 97         { 98             int a, b; 99             scanf("%d%d", &a, &b);100             X[m]=a;101             ss[m++]=Seg(a, a+w, b, 1);102             X[m]=a+w;103             ss[m++]=Seg(a, a+w, b+h, -1);104         }105         sort(X, X+m);106         sort(ss, ss+m);107         int k=unique(X, X+m)-X;108         int ans=0;109         memset(len, 0, sizeof(len));110         memset(cnt, 0, sizeof(cnt));111         for(int i=0;i<m;i++)112         {113             int l=lower_bound(X, X+k, ss[i].l)-X;114             int r=lower_bound(X, X+k, ss[i].r)-X;115             Update(l, r, ss[i].s, 0, k-1, 1);116             ans=max(ans, len[1]);117         }118         printf("%d\n", ans);119     }120     return 0;121 }