Codeforces Round #345 (Div. 2) A. Joysticks

A. Joysticks

time limit per test
1 second

memory limit per test
256 megabytes

input
standard input

output
standard output

Friends are going to play console. They have two joysticks and only one charger for them. Initially first joystick is charged at a1 percent
and second one is charged at a2 percent.
You can connect charger to a joystick only at the beginning of each minute. In one minute joystick either discharges by 2 percent (if not connected to a charger) or charges by 1 percent (if connected to a charger).

Game continues while both joysticks have a positive charge. Hence, if at the beginning of minute some joystick is charged by 1 percent, it has to be connected to a charger, otherwise the game stops. If some joystick completely discharges (its charge turns to
0), the game also stops.

Determine the maximum number of minutes that game can last. It is prohibited to pause the game, i. e. at each moment both joysticks should be enabled. It is allowed for joystick to be charged by more
than 100 percent.

Input

The first line of the input contains two positive integers a1 and a2 (1 ≤ a1, a2 ≤ 100),
the initial charge level of first and second joystick respectively.

Output

Output the only integer, the maximum number of minutes that the game can last. Game continues until some joystick is discharged.

Examples

input

3 5

output

6

input

4 4

output

5

Note

In the first sample game lasts for 6 minute by using the following algorithm:

at the beginning of the first minute connect first joystick to the charger, by the end of this minute first joystick is at 4%, second is at 3%;

continue the game without changing charger, by the end of the second minute the first joystick is at 5%, second is at 1%;

at the beginning of the third minute connect second joystick to the charger, after this minute the first joystick is at 3%, the second one is at 2%;

continue the game without changing charger, by the end of the fourth minute first joystick is at 1%, second one is at 3%;

at the beginning of the fifth minute connect first joystick to the charger, after this minute the first joystick is at 2%, the second one is at 1%;

at the beginning of the sixth minute connect second joystick to the charger, after this minute the first joystick is at 0%, the second one is at 2%.

After that the first joystick is completely discharged and the game is stopped.

题意：两个游戏机联机玩游戏，你有一个充电器，你能用充电器1s内为其中一个游戏机充电1%，另一个游戏机1s要消耗电量2%，问你怎么样玩游戏时间达到最长，ps 联机游戏当然是只要其中一个游戏机没电就停止啦。输入两个游戏机的初始电量，输出最长游戏时间。

题目不难，就是有坑。就是当两个游戏机的电量都为1的时候，这时无论你为那个游戏机充电都没办法坚持1s的时间（1s要消耗电量2%），所以不能加上这1s。

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
using namespace std;
int main()
{
int a,b,ans=0;
cin>>a>>b;
while(a>0&&b>0){
if(a==1&&b==1)break;
if(a<b){
a++;
b-=2;
ans++;
}
else{
b++;
a-=2;
ans++;
}
}
cout<<ans<<endl;
return 0;
}