// ref:
// https://yukicoder.me/submissions/994182 by kotatsugame

#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define wt(v) ({ulong _z=v;do*--wp=_z%10+48;while(_z/=10);})
#define wt1(v) ({char wbuf[64],*wp=wbuf+sizeof wbuf;wt(v);write(1,wp,wbuf+sizeof wbuf-wp);})
#define chmin(v,a) (v=v<=a?v:a)
#define chmax(v,a) (v=v>=a?v:a)

typedef unsigned long ulong;

int N,S,H,L,Z,R[2<<17],ql[2<<17];
long dp[2<<17],ZS[2<<17],qz[2<<17];

int main()
{
	rd_init();
	N=rd();
	S=rd();
	H=rd();
	L=R[0]=-H;
	long zs=0;
	int qr=0,qw=0;
	int l=0;
	long mx=0;
	for(int i=1;i<=N;i++)
	{
		L=rd();
		R[i]=rd();
		Z=rd();
		zs+=Z;
		ZS[i+1]=ZS[i]+Z;
		dp[i]=dp[i-1]+Z;
		while(R[l+1]+H<=L)l++;
		long tz=dp[l]+ZS[i]-ZS[l+1];
		while(qr<qw&&qz[qw-1]>=tz)--qw;
		qz[qw]=tz;
		ql[qw]=L;
		++qw;
		while(qr<qw&&ql[qr]+S<R[i])++qr;
		if(qr<qw)chmin(dp[i],qz[qr]);
		chmax(mx,dp[i]);
	}
	wt1(zs-mx);
}