#include<bits/stdc++.h>
using std::cin;
using std::cout;
using std::endl;
using std::vector;
int main(){
    int N,M; cin>>N>>M;
    if(N>1000){
        cout<<M-1<<endl;
        return 0;
    }
    const int max=1e5,inf=1e9;
    assert(1<=N&&N<=max&&1<=M&&M<=max);
    vector<int> A(N);
    int ans=0,sum=0;
    std::set<int> set;
    set.insert(M);
    for(int i=0;i<N;i++){
        cin>>A[i];
        assert(1<=A[i]&&A[i]<=inf);
        sum+=A[i]%M;
        sum%=M;
        ans=std::max(ans,sum+M-*set.upper_bound(sum));
        set.insert(sum);
    }
    cout<<ans<<endl;
}