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

#define getrp() ({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd_skip() while(*rp++>=48)
#define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define wt(v) ({unsigned _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 f(a) (a>0?(a)*(a+1):0)
#define MD 998244353

int main(){
	char*rp=getrp();
	rd_skip();
	int w=rd();
	rd_skip();
	long z=0;
	while(*rp){
		long x=rd();
		long y=rd();
		long v=rd();
		z=(z+v*(x*x-(f(x-y)+f(x-(w+1-y))>>1)))%MD;
	}
	wt1(z);
	_exit(0);
}