#include <stdio.h>

int N,A[18],B[18]; bool C[1<<18][18];

bool chk(int x)
{
	for (int j=1;j<(1<<N);j++) for (int i=0;i<N;i++) C[j][i] = 0;
	for (int i=0;i<N;i++) C[1<<i][i] = 1;
	for (int j=1;j<(1<<N);j++){
		for (int i=0;i<N;i++) if (C[j][i]){
			for (int k=0;k<N;k++) if (~j & (1 << k)){
				if (B[i] - A[i] + A[k] <= x) C[j+(1<<k)][k] = 1;
			}
		}
	}

	bool g = 0;
	for (int i=0;i<N;i++) if (C[(1<<N)-1][i]) g = 1;
	return g;
}

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

	int l = 0, r = 2222;
	while (l + 1 < r){
		int m = (l + r) / 2;
		if (chk(m)) r = m;
		else l = m;
	}
	printf ("%d\n",r);
	return 0;
}