#
# Complete the 'maximumSum' function below.
#
# The function is expected to return a LONG_INTEGER.
# The function accepts following parameters:
#  1. LONG_INTEGER_ARRAY a
#  2. LONG_INTEGER m
#

import typing

class A(typing.NamedTuple):
    i: int
    v: int

def maximumSum(a, m):
    psum = 0
    x = []
    for i, v in enumerate(a):
        psum = (psum + v) % m
        x.append(A(i, psum))
    
    x = sorted(x, key=lambda e: e.v)
    # print(x)
    
    mx = x[-1].v
    for (i1, v1), (i2, v2) in zip(x[:-1], x[1:]):
        if (i1 > i2):
            mx = max(mx, v1 - v2 + m)

    return mx