import sys

sys.setrecursionlimit(500 * 500)

# if 'pypyjit' in sys.builtin_module_names:
#     import pypyjit
#     pypyjit.set_param('max_unroll_recursion=-1')
input = sys.stdin.readline
from math import gcd
from functools import reduce

# product('ABCD', repeat=2) => AA AB AC AD BA BB BC BD CA CB CC CD DA DB DC DD
from itertools import product

# permutations('ABCD', 2) => AB AC AD BA BC BD CA CB CD DA DB DC
from itertools import permutations

# combinations('ABCD', 2) => AB AC AD BC BD CD
from itertools import combinations
from itertools import accumulate  # 累積和作るやつ
from collections import deque
from collections import defaultdict
from heapq import heappop, heappush
from bisect import bisect_left

# 0埋めされた二進数表現
f"{9:05b}"

alpha2num = lambda c: ord(c) - ord("a")
num2alpha = lambda c: chr(c + ord("A"))
popcnt = lambda x: bin(x).count("1")

# 数値判定
"1".isdigit()


dh = [-1, 0, 1, 0]
dw = [0, -1, 0, 1]
dh8 = [-1, -1, -1, 0, 0, 1, 1, 1]
dw8 = [-1, 0, 1, -1, 1, -1, 0, 1]


def resolve():
    inf = 10**18 + 1
    N, X = map(int, input()[:-1].split(" "))
    c = num2alpha((X // N) - 1)

    print(c)


resolve()
