#include "bits/stdc++.h"
using namespace std;
using LLI = long long;
#define INF 999999999
#define MOD 1000000007
#define FOR(i, s, e) for(LLI i = s, i##_lim = (e); i < i##_lim; i++)
#define FORR(i, s, e) for(LLI i = s-1, i##_lim = (e); i##_lim<=i; i--)
#define REP(i, n) FOR(i,0,n)
#define REPR(i, n) FORR(i,n,0)
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#define bit(a, shift) ((a>>shift)&1))
#define pm(a) ((a)?1:-1)
#define SORT(v) sort(v.begin(),v.end())
#define RSORT(v) sort((v).rbegin(), (v).rend())
#define Mat2(type,name,h,w,def) vector<vector<type>> name(h,vector<type>(w, def))
#define Mat3(type,name,h,w,d,def) vector<vector<vector<type>>> name(h,vector<vector<type>>(w, vector<int>(d,def)))
// int 2.14E±9    LLIi 9.2E±18    double 1.7E±380


int main()
{
	cout << fixed << setprecision(10);

	LLI n, x;
	cin >> n >> x;
	LLI sum = 0;
	REP(i, n)
	{
		LLI s;
		cin >> s;
		sum += s;
	}
	cout << sum % x;

	return 0;
}