20250809

# import sys
# sys.setrecursionlimit(100000)
#
# n=int(input())
# D=[]
# for x in range(n+1):
#     D.append(0)
# def f(n):
#     global D
#     if D[n]==0:
#         if n>3:
#             D[n]=(f(n-1)%1000+f(n-2)%1000+f(n-3)%1000)%1000
#             return(D[n])
#         elif n==3:
#             D[n]=4
#             return(4)
#         elif n==2:
#             D[n]=2
#             return(2)
#         else:
#             D[n]=1
#             return(1)
#     else:
#         return (D[n])
# print(f(n))

# import sys
# sys.setrecursionlimit(10000)
# G=[0]
# n=int(input())
# D=[0]
# for x in range(n):
#     D.append(int(input()))
#     G.append(0)
# def f(n):
#     if G[n]==0:
#         if n>3:
#             G[n]=max(f(n-3)+D[n-1], f(n-2))+D[n]
#             return(G[n])
#         elif n==3:
#             G[n]=max(D[1], D[2])+D[3]
#             return(G[n])
#         elif n==2:
#             G[n]=(D[1]+D[2])
#             return(G[n])
#         else:
#             G[n]=D[1]
#             return(D[1])
#     else:
#         return(G[n])
# print(f(n))

D=[]
n=int(input())
k=0
while n>=27:
    while n>=27:
        if k==27:
            break
        k+=1
        n-=26
    D.append(chr(64+n))
D.append(chr(64+k))
print(D)