#include <stdio.h>

int min(int arr[], int len) {
    if (len == 1) return arr[0];
    int m = arr[0];
    for (int i = 0; i < len; i++)
        if (arr[i] < m) m = arr[i];
    return m;
}

int solution(int arr[], int len, int delta) {
    int count[delta];
    int distance;
    
    for (int i = 0; i < delta; i++) count[i] = 0;
    
    for (int i = 0; i < len; i++) {
        distance = delta - arr[i] % delta;
        for (int j = 0; j < delta; j++) {
            count[j] += (distance + j) % delta;
        }
    }
    
    return min(count, delta);
}

int main() {
    int len, delta;
    scanf("%d", &len); scanf("%d", &delta);
    int arr[len];
    for (int i = 0; i < len; i++) scanf("%d", &arr[i]);
    printf("%d", solution(arr, len, delta));
}