DB = int(input()) DY = int(input()) YB = int(input())

if DB<=(DY+YB) or DY<=(DB+YB) or (YB<=(DB+DY)): print('error!') if DB==DY and DB==YB and YB==DY: print('等边三角形') elif DB==DY or DB==YB or YB==DY: print('等腰三角形')