from sys import stdin
mb=0
mv=0
a=0
for s in stdin:
 if 'END' in s:
  break
 _=s.split()
 n=_[0]
 mb,mv=float(_[1]),float(_[2])
 a=mb-mv
 if a>=-0.35 and a<=-0.251:
  print(f'{n} {a:.2f} O')
 elif a>=-0.25 and a<=-0.001:
  print(f'{n} {a:.2f} B')
 elif a>=0.00 and a<=0.249:
  print(f'{n} {a:.2f} A')
 elif a>=0.250 and a<=0.499:
  print(f'{n} {a:.2f} F')
 elif a>=0.500 and a<=0.999:
  print(f'{n} {a:.2f} G')
 elif a>=1.0 and a<=1.499:
  print(f'{n} {a:.2f} K')
 elif a>=1.5 and a<=2.0:
  print(f'{n} {a:.2f} M')