Farmer John has hired a professional photographer to take a picture of some of his cows. Since FJ's cows represent a variety of different breeds, he would like the photo to contain at least one cow from each distinct breed present in his herd. FJ's $N$ cows are all standing at various positions along a line, each described by an integer position (i.e., its x coordinate) as well as an integer breed ID. FJ plans to take a photograph of a contiguous range of cows along the line. The cost of this photograph is equal its size -- that is, the difference between the maximum and minimum x coordinates of the cows in the range of the photograph. Please help FJ by computing the minimum cost of a photograph in which there is at least one cow of each distinct breed appearing in FJ's herd.

Line $1$: The number of cows, $N$ $(1 \le N \le 50,000)$. Lines $2\cdots 1+N$: Each line contains two space-separated positive integers specifying the x coordinate and breed ID of a single cow. Both numbers are at most $1$ billion.

Line $1$: The smallest cost of a photograph containing each distinct breed ID.

The range from $x=22$ up through $x=26$ (of total size $4$) contains each of the distinct breed IDs $1$, $3$, and $7$ represented in FJ's herd.