Editorial

Farmer John has the following manure movement options:

• Drive directly from $a$ to $b$, covering the distance $|a–b|$;

  

• Drive a tractor from $a$ to $x$, teleport from $x$ to $y$, and then drive the tractor again from $y$ to $b$. The total distance covered by the tractor is $|a-x|+|b-y|$;

  

• Drive a tractor from $a$ to $y$, teleport from $y$ to $x$, and then drive the tractor again from $x$ to $b$. The total distance covered by the tractor is $|a-y|+|b-x|$;

  

The smallest of these three values will be the answer.

Example

In the given example, the best strategy is to haul the manure from position $3$ to position $2$, teleport it to position $8$, and then haul it to position $10$. The total distance covered by the tractor is therefore $1+2=3$.

Algorithm realization

Read the input data.

scanf("%d %d %d %d", &a, &b, &x, &y);

Find the answer — the minimum of the three values.

res = abs(a - b);
res = min(res, abs(a - x) + abs(b - y));
res = min(res, abs(a - y) + abs(b - x));

Print the answer.

printf("%d\n", res);

Python realization

Read the input data.

a, b, x, y = map(int, input().split())

Find the answer — the minimum of the three values.

res = abs(a - b)
res = min(res, abs(a - x) + abs(b - y))
res = min(res, abs(a - y) + abs(b - x))

Print the answer.

print(res)