N=int(input())
c=[]
for i in range(N):
    l,r=map(int,input().split())
    c.append([l,r-l])
dp=[[0]*N for _ in range(1<<N)]
for i in range(1,1<<N):
    for j in range(N):
        if not i&(1<<j):continue
        for k in range(N):
            kk=1<<k
            cc=c[j][1]+c[k][0]
            if j==k or i&(1<<k):continue
            if dp[i^kk][k]==0:
                dp[i^kk][k]=max(dp[i][j],cc)
            else:
                dp[i^kk][k]=min(dp[i^kk][k],max(dp[i][j],cc))
print(min(dp[-1]))