#include <stdio.h>
#include <math.h>

int keta(int N,int keta,int K){
    for(int i =0;i<=keta;i++){
        N*=keta;
    }
    return keta;
}
int read(){
    int x=0; char c;
    while(((c=getchar())>'9' || c<'0')&&c!='-');
    const int f=(c=='-')&&(c=getchar());
    while(x=x*10-48+c,(c=getchar())>='0'&&c<='9');
    return f?-x:x;
}
int main(void){
    int N=read();
    int K=read();
    int x = 0;
    int y = 0;
    int buf = 0;
    for(int i = 0;i<N;i++){
        x += (pow(K,N-1-i)*(buf=read()));
        y +=buf;
    }
    printf("%d",x%y);
    return 0;
    
}