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

char*mmap();
char wbuf[1<<25];

#define rd_skip() while(*rp++>=48)
#define rd_skip_line() while(*rp++!=10)
#define rd(v) long v=0;{long _c;while(_c=*rp++-48,_c>=0)v=v*10+_c;}
#define WTHI(v) {long _z=v,_n=0,_d=0;while(++_n,_d=_d<<8|0x30|_z%10,_z/=10);*(long*)wp=_d;wp+=_n;}
#define WTLO(v) {long _z=v,_n=8,_d=0;while(_d=_d<<8|0x30|_z%10,_z/=10,--_n);*(long*)wp=_d;wp+=8;}
#define wt(v) if(v>=100000000){*wp++=v/100000000+48;WTLO(v);}else{WTHI(v);}

unsigned d[4001][4001];

#define MD 998244353

void f0(){
	for(long x=0;x<=4000;++x){
		d[0][x]=1;
	}
	for(long y=1;y<=4000;++y){
		d[y][0]=1;
		for(long x=1;x<=4000;++x){
			long a=d[y-1][x-1]*2;
			a-=a<MD?0:MD;
			a+=d[y-1][x];
			a-=a<MD?0:MD;
			a+=d[y][x-1];
			a-=a<MD?0:MD;
			d[y][x]=a;
		}
	}
	for(long y=1;y<=4000;++y){
		for(long x=1;x<=4000;++x){
			long a=d[y-1][x-1]+d[y][x];
			a-=a<MD?0:MD;
			d[y][x]=a;
		}
	}
}

void f1(){
	char*rp=mmap(0l,1l<<25,1,2,0,0ll);
	char*wp=wbuf;

	rd_skip();
	while(*rp){
		rd(x);
		rd(y);
		long a=d[y][x];
		wt(a);
		*wp++='\n';
	}

	write(1,wbuf,wp-wbuf);
	_exit(0);
}

main(){
	f0();
	f1();
}