[zerojudge] d984: 棄保效應

from sys import stdin

op = 'ABC'
for s in stdin:
    f = [[i, int(c)] for i, c in enumerate(s.split())]
    f.sort(key = lambda z: z[1])
    t = f.pop(0)
    f[0][1] += t[1]
    f.sort(key = lambda z: -z[1])
    print(op[f[0][0]])