bash-pure, 85 bytes

Result

TLE

Code [DL]

f(){
read l
if [ ${l:1:1} = ${l:2:1} ];then
echo ${l:1:1}
else echo ${l:4:1}
fi
f
}
f

stdin

722 227
647 549
494 687
533 336
288 865
522 554
462 612
814 194
426 773
327 728
877 753
314 345
846 668
958 863
176 966
371 719
817 882
494 795
539 337
837 338
918 186
355 256
242 288
736 331
366 738
249 946
478 168
688 918
921 792
788 589
122 663
154 442

stdout

stderr

strace