#include <stdio.h>

const int non = 0x7fffffff;
int N,A[18],B[18],C[1<<18][18];

int max(int a, int b){return a > b ? a : b;}

int main()
{
	scanf ("%d",&N);
	for (int i=0;i<N;i++) scanf ("%d %d",&A[i],&B[i]);

	for (int j=1;j<(1<<N);j++) for (int i=0;i<N;i++) C[j][i] = non;
	for (int i=0;i<N;i++) C[1<<i][i] = 0;
	for (int j=1;j<(1<<N);j++){
		for (int i=0;i<N;i++) if (C[j][i] != non){
			for (int k=0;k<N;k++) if (~j & (1 << k)){
				int &a = C[j^(1<<k)][k];
				int x = max(B[i] - A[i] + A[k], C[j][i]);
				if (a > x) a = x;
			}
		}
	}

	int ans = non;
	for (int i=0;i<N;i++) if (ans > C[(1<<N)-1][i]) ans = C[(1<<N)-1][i];
	printf ("%d\n",ans);

	return 0;
}