#include <cstdio>

 #include <cstring>

 #include <string>

 #include <algorithm>

 using namespace std;

 #define maxn 50100

 #define lson l,m,rt<<1

 #define rson m+1,r,rt<<1|1

 #define LL __int64

 struct node

 {

     LL lx,rx,y;

     LL s;

     node(){}

     node(LL a,LL b,LL c,LL d):lx(a),rx(b),y(c),s(d){}

     bool operator < (const node &S) const

     {

         if(y == S.y)

         return s > S.s;

         else

         return y < S.y;

     }

 }mat[maxn];

 LL que[*maxn];

 LL tree[*maxn];

 LL lz[*maxn];

 void pushup(int rt)

 {

     tree[rt] = max(tree[rt<<],tree[rt<<|]);

 }

 void pushdown(int rt)

 {

     if(lz[rt])

     {

         lz[rt<<] += lz[rt];

         lz[rt<<|] += lz[rt];

         tree[rt<<] += lz[rt];

         tree[rt<<|] += lz[rt];

         lz[rt] = ;

     }

 }

 void update(int L,int R,int c,int l,int r,int rt)

 {

     int m;

     if(L <= l&&r <= R)

     {

         tree[rt] += c;

         lz[rt] += c;

         return ;

     }

     pushdown(rt);

     m = (l+r)>>;

     if(L <= m)

     update(L,R,c,lson);

     if(R > m)

     update(L,R,c,rson);

     pushup(rt);

 }

 int bin(LL x,int n)

 {

     int str,mid,end;

     str = ;

     end = n;

     while(str <= end)

     {

         mid = (str+end)/;

         if(que[mid] == x)

         return mid;

         else if(que[mid] > x)

         end = mid - ;

         else

         str = mid + ;

     }

     return mid;

 }

 int main()

 {

     int n,num,k,i;

     LL a,b,c,h,w;

     while(scanf("%d%I64d%I64d",&n,&w,&h)!=EOF)

     {

         num = ;

         w--;

         h--;

         for(i = ;i < n;i ++)

         {

             scanf("%I64d%I64d%I64d",&a,&b,&c);

             mat[num] = node(a,a+w,b,c);

             que[num++] = a;

             mat[num] = node(a,a+w,b+h,-c);

             que[num++] = a+w;

         }

         k = ;

         sort(que,que+num);

         sort(mat,mat+num);

         for(i = ;i < num;i ++)

         {

             if(que[i] != que[i-])

             que[k++] = que[i];

         }

         LL maxz = ;

         memset(tree,,sizeof(tree));

         memset(lz,,sizeof(lz));

         for(i = ;i < num;i ++)

         {

             int l = bin(mat[i].lx,k-);

             int r = bin(mat[i].rx,k-);

             if(l <= r) update(l,r,mat[i].s,,k-,);

             maxz = max(maxz,tree[]);

         }

         printf("%I64d\n",maxz);

     }

     return ;

 }