https://www.acmicpc.net/problem/10986
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
public class Main {
static int N, M;
static long answer;
static long[] prefixSum, count;
static void input() {
Reader scanner = new Reader();
N = scanner.nextInt();
M = scanner.nextInt();
prefixSum = new long[N + 1];
count = new long[M];
answer = 0;
for(int idx = 1; idx <= N; idx++) {
prefixSum[idx] = (prefixSum[idx - 1] + scanner.nextInt()) % M;
if(prefixSum[idx] == 0) answer++;
count[(int)prefixSum[idx]]++;
}
}
static void solution() {
for(int idx = 0; idx < M; idx++)
answer += count[idx] * (count[idx] - 1) / 2;
System.out.println(answer);
}
public static void main(String[] args) {
input();
solution();
}
static class Reader {
BufferedReader br;
StringTokenizer st;
public Reader() {
br = new BufferedReader(new InputStreamReader(System.in));
}
String next() {
while(st == null || !st.hasMoreElements()) {
try {
st = new StringTokenizer(br.readLine());
} catch (IOException e) {
e.printStackTrace();
}
}
return st.nextToken();
}
int nextInt() {
return Integer.parseInt(next());
}
}
}