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

long keta(long N,long keta,long K){
    for(long 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){
    long N=read();
    long K=read();
    long long x = 0;
    long long y = 0;
    long long buf = 0;
    for(int i = 0;i<N;i++){
        x += (pow(K,N-1-i)*(buf=read()));
        y +=buf;
    }
    printf("%ld",x%y);
    return 0;
    
}