/**
 * Tittle:	10268 - 498-bis
 * Author:	Cheng-Shih, Wong
 * Date:	2015/05/02
 */

// include files
#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>

using namespace std;

// definitions
#define FOR(i,a,b) for( int i=(a),_n=(b); i<=_n; ++i )
#define clr(x,v) memset( x, v, sizeof(x) )

typedef vector<int> VI;

// declarations
int x;
int ans;

// functions
void solve( void )
{
	static int tmp, base, cnt;
	static VI bucket;

	bucket.clear();

	scanf( "%d", &tmp );
	bucket.push_back(tmp);

	while( getchar()!='\n' ) {
		scanf( "%d", &tmp );
		bucket.push_back(tmp);
	}

	ans = 0;
	cnt = base = 1;
	for( int i = bucket.size()-2; i>=0; --i ) {
		ans += cnt*bucket[i]*base;

		++cnt;
		base *= x;
	}

	printf( "%d\n", ans );
}

// main function
int main( void )
{

	// input
	while( scanf( "%d", &x )==1 ) {
		solve();
	}

	return 0;
}