{"input":[[-4,-1,2,7],1],"expected":[1,2],"label":"Unique neg+pos: -1+2=1 at [1,2]"}
{"input":[[2147483646,1],2147483647],"expected":[0,1],"label":"Near max-int: 2147483646+1=2147483647"}
{"input":[[1,2,3,4,5,6,7,8,9,10,11,12,13,14],27],"expected":[12,13],"label":"Pair at end: 13+14=27"}
