Hlg2157 [query Rules]

Eat beans

Time Limit: 1000 MS Memory limit: 32768 K Total submit: 59 (40 Users) Total accepted: 34 (34 Users) Rating: Special Judge: No

Description

One day, woods and his grilfriend (GF) came to a fairy tale Kingdom town with many peas (for example, every circle in it is a bean), each of which goes east, south, roads in the West, North, southeast, northeast, northwest, and Southwest China directions. The distance between a straight line road and a diagonal line road is 1 meters, and the distance between the two lines is 2 meters. GF becomes hungry as soon as it sees it ...... Can you calculate the shortest path to get back to the starting point after eating all the beans once?   For a 2x3 graph, the shortest distance (as shown in the Red Line) is 6 meters.

Input

Multiple groups of test data. One row of test data in each group, including two integers n, m (1 <m <50 and 1 <n <50.), indicates that the graph size is n rows of M columns.

Output

Output a row of data in each group, and only eat all the beans once. The shortest path is returned to the start point. (Precise to two decimal places ).

Sample Input

2 2 2 3

Sample output

4.00 6.00

Hint

Source

2014 summer training and exercises (March August 13)

Analysis: Finding rules

Code:

 1 #include <iostream> 2 #include <cstdio> 3 #include <cmath> 4 using namespace std; 5  6 int main() { 7     int a, b; 8     while(EOF != scanf("%d %d",&a, &b) ) { 9         double ans = a * b + 1e-9;10         if(a % 2 == 1 && b % 2 == 1) ans += sqrt(2) - 1.0;11         printf("%.2lf\n",ans);12     }13     return 0;14 }

View code

 

Hlg2157 [query Rules]