BJ 2961道英で作ったグルメ

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
	static int N, R, minGap, multi, sum; // 차이, 곱(신맛), 합(쓴맛).
	static int[][] input;
	static int[] numbers;
	static BufferedReader br;
	static BufferedWriter bw;
	static StringTokenizer st;
	
	public static void combination(int cnt, int start) { // 현재 자리에 수 뽑기.
		if(cnt == R) {
			int gap = Math.abs(multi - sum);
			if(gap < minGap) {
				minGap = gap;
			}
			//System.out.println(Arrays.toString(numbers));
			return;
		}
			
			
		// 입력받은 모든 수를 현재 자리에 넣어보기(유도파트)
		for(int i = start; i < N; i++) {
			multi *= input[i][0];
			sum += input[i][1];
			
			combination(cnt + 1, i + 1);	
			multi /= input[i][0];
			sum -= input[i][1];
			
		}
		
	}
	
	
	public static void main(String[] args) throws IOException {
		br = new BufferedReader(new InputStreamReader(System.in));
		bw = new BufferedWriter(new OutputStreamWriter(System.out));
		N = Integer.parseInt(br.readLine());
		
		input = new int[N][2];
		numbers = new int[N];
		
		for(int i = 0; i < N; i++) {
			st = new StringTokenizer(br.readLine(), " ");
			input[i][0] = Integer.parseInt(st.nextToken());
			input[i][1] = Integer.parseInt(st.nextToken());			
		}
		minGap = Math.abs(input[0][0] - input[0][1]);
		for(int i = 1; i <= N; i++) {
			multi = 1;
			sum = 0;
			R = i;
			combination(0, 0);
			
		}
		
		System.out.println(minGap);
	}
}