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

char*mmap();
#define rd_skip() while(*rp++>=48)
#define rd(v) int v=0;{int _c;while(_c=*rp++-48,_c>=0)v=v*10+_c;}

char wbuf[1<<28];

#define rep(v,e) for(int v=0;v<e;++v)
#define rrep(v,e) for(int v=e;v--;)

int s[400004];

main(){
	char*rp=mmap(0l,1l<<28,1,2,0,0ll);
	rd(n);
	rd(q);
	{
		int*sp=s+4;
		rep(i,q){
			rd(a);
			*sp=a;
			sp+=4;
		}
	}
	{
		int*sp=s+5;
		rep(i,q){
			rd(b);
			*sp=b;
			sp+=4;
		}
	}

	{
		int*sp=s;
		int lb=1,rb=n;
		*sp++=0;
		*sp++=0;
		*sp++=lb;
		*sp++=rb;
		rep(i,q){
			int a=*sp++;
			int b=*sp++;
			if(a>b){
				int t=a;a=b;b=t;
			}
			if(lb==1&&a==1&&b==2){
				lb=3;
			}else if(lb-1!=a){
				if(lb-1!=b&&lb>1){
					--lb;
				}
			}else{
				if(lb==b){
					++lb;
				}
			}
			if(rb==n&&a==n-1&&b==n){
				rb=n-2;
			}else if(rb+1!=b){
				if(rb+1!=a&&rb<n){
					++rb;
				}
			}else{
				if(rb==a){
					--rb;
				}
			}
			if(lb>rb){
				write(1,"NO",2);
				_exit(0);
			}
			*sp++=lb;
			*sp++=rb;
		}

		char*wp=wbuf+sizeof wbuf;
		int c=0;
		rrep(i,q+1){
			int rb=*--sp;
			int lb=*--sp;
			int b=*--sp;
			int a=*--sp;
			if(c<lb){
				c=lb;
			}
			if(c>rb){
				c=rb;
			}
			if(c==a|c==b){
				c=c==1|a==c-1|b==c-1?c+1:c-1;
			}
			*--wp=10;
			int v=c;
			do{
				*--wp=v%10+48;
			}while(v/=10);
		}
		*--wp=10;
		*--wp='S';
		*--wp='E';
		*--wp='Y';
	
		write(1,wp,wbuf+sizeof wbuf-wp);
		_exit(0);
	}
}