#include <bits/stdc++.h>
using namespace std;
long long pwr(long long base, long long p, long long mod = (1000000007LL)) {
  long long ans = 1;
  while (p) {
    if (p & 1) ans = (ans * base) % mod;
    base = (base * base) % mod;
    p /= 2;
  }
  return ans;
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long nCr(long long n, long long r) {
  long long C[r + 1];
  memset(C, 0, sizeof(C));
  C[0] = 1;
  for (long long i = 1; i <= n; i++)
    for (long long j = min(i, r); j > 0; j--) C[j] = C[j] + C[j - 1];
  return C[r];
}
bool isPrime(long long n) {
  if (n <= 1) return false;
  if (n == 2) return true;
  if (n % 2 == 0) return false;
  long long m = sqrt(n);
  for (long long i = 3; i <= m; i += 2)
    if (n % i == 0) return false;
  return true;
}
long long M(long long a) { return (a % (1000000007LL)); }
bool isPowerOfTwo(long long x) { return x && (!(x & (x - 1))); }
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(0);
  long long n, p;
  cin >> n >> p;
  long long sum = 0;
  vector<long long> v(n);
  for (long long i = 0; i < (long long)(n); ++i) {
    cin >> v[i];
    sum += v[i];
  }
  long long ans = -1;
  long long x = 0;
  for (long long i = 0; i < n; i++) {
    if (i == n - 1) break;
    x += v[i];
    long long y = sum - x;
    ans = max(ans, x % p + y % p);
  }
  cout << ans;
  return 0;
}
