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

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

#define rd_skip() while(*rp++>=48)
#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) WTHI(v)
#define rep(v,e) for(long v=0;v<e;++v)
#define rep3(v,s,e) for(long v=s;v<e;++v)

int ab[200002];
int nc[200002];
int pa[200002];
int st[100002];

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

	rd(n);
	rd_skip();

	long sn=0;
	st[sn++]=0;

	rep3(i,1,n+1){
		if(!(*rp++&1)){
			pa[i]=st[sn-1];
			++nc[st[sn-1]];
			st[sn++]=i;
		}else{
			long j=st[--sn];
			ab[i]=j;
			ab[j]=i;
		}
	}
	++rp;
	ab[0]=n+1;
	ab[n+1]=0;
	rep3(i,1,n+1){
		if(nc[pa[i]]==1){
			pa[i]=pa[pa[i]];
		}
	}

	while(*rp){
		rd(x); if(ab[x]<x) x=ab[x];
		rd(y); if(ab[y]<y) y=ab[y];
		if(ab[x]>ab[y]){
			long t=x;
			x=y;
			y=t;
		}
		while(x<y){
			y=pa[y];
		}
		if(y==0){
			*(int*)wp=*(int*)"-1\n";
			wp+=3;
		}else{
			wt(y);
			*wp++=' ';
			y=ab[y];
			wt(y);
			*wp++='\n';
		}
	}
	write(1,wbuf,wp-wbuf);
	_exit(0);
}