#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;

int main() {
    int n, m;
    while(cin >> n >> m, n){
        vector<ll> v(n);
        for (auto &&i : v) scanf("%lld", &i);
        ll S = 0;
        set<ll> s;
        s.emplace(0);
        ll ans = 0;
        for (int i = 0; i < n; ++i) {
            (S += v[i]) %= m;
            auto a = s.upper_bound(S);
            if(a != s.end()){
                ans = max(ans, (S-*a+m)%m);
            }else {
                ans = max(ans, S-*s.begin());
            }
            s.emplace(S);
        }
        cout << ans << "\n";
    }
    return 0;
}
