A =[i for i in range(-100, 100)]
B = []
Max = -10**10
for i in range(len(A)):
    if A[i] < 0 and abs(A[i]) % 10 == 3:
        B = B.append(A[i])
        if len(B) == 7:
            Max = max(Max, sum(B))
        else:
            continue
    else:
        B = []
print(Max)