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

#define rd() ({long _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 repeat(e) for(typeof(e)_=e;_--;)

typedef unsigned long ulong;

int main(){
	void*mmap();
	long(*f)(long)=mmap(0l,1l<<21,7,34,-1,0l);
	char*fwp=f;
	memcpy(fwp,"\xf3\x0f\x1e\xfa",4);
	fwp+=4;
	char*rp=mmap(0l,1l<<25,1,2,0,0l);
	int q=rd();
	long y=rd();
	repeat(q){
		int c=*rp;
		if(c>='0'&&c<='9'){
			*fwp++=0x48;
			*fwp++=0xb8;
			*(long*)fwp=rd();
			fwp+=8;
			*fwp++=0x50;
		}else if(c=='X'){
			rp+=2;
			*fwp++=0x57;
		}else{
			if(c=='+'){
				rp+=2;
				memcpy(fwp,"\x58\x5a\x48\x01\xd0\x50",6);
				fwp+=6;
			}else{
				rp+=4;
				if(rp[-3]=='a'){
					memcpy(fwp,"\x58\x5a\x48\x39\xc2\x48\x0f\x4d\xc2\x50",10);
				}else{
					memcpy(fwp,"\x58\x5a\x48\x39\xc2\x48\x0f\x4c\xc2\x50",10);
				}
				fwp+=10;
			}
		}
	}
	*fwp++=0x58;
	*fwp++=0xc3;
	{
		long a=-1;
		long b=y;
		while(a+1<b){
			long m=a+b>>1;
			long v=f(m);
			if(v<y){
				a=m;
			}else{
				b=m;
			}
		}
		if(f(b)==y){
			wt1(b);
		}else{
			write(1,"-1",2);
		}
	}
	_exit(0);
}