Two people are playing a game with a string ss, consisting of lowercase latin letters.
On a player's turn, he should choose two consecutive equal letters in the string and delete them.
For example, if the string is equal to "xaax" than there is only one possible turn: delete "aa", so the string will become "xx". A player not able to make a turn loses.
Your task is to determine which player will win if both play optimally.
Input
The only line contains the string ss, consisting of lowercase latin letters (1≤|s|≤100000), where |s||s| means the length of a string ss.
Output
If the first player wins, print "Yes". If the second player wins, print "No".
Examples
input
Copy
abacaba
output
Copy
No
input
Copy
iiq
output
Copy
Yes
input
Copy
abba
output
Copy
No
Note
In the first example the first player is unable to make a turn, so he loses.
In the second example first player turns the string into "q", then second player is unable to move, so he loses.
思路：我们可以用栈来很好的表示这个过程，如果要入栈的字符和栈顶不一样，我们则将该元素压入栈中，如果要压入的元素和栈顶元素相同，我们则让栈顶元素出栈，但这个过程一定要满足栈不为空
代码：
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<stack>
using namespace std;
char a[1000005];
stack<char> s;
int main()
{
scanf("%s",a);
int len=strlen(a);
s.push(a[0]);
int sum=0;
for(int t=1;t<len;t++)
{
if(!s.empty()&&a[t]==s.top())
{
s.pop();
sum++;
continue;
}
else
{
s.push(a[t]);
}
}
if(sum%2==0)
{
cout<<"No"<<endl;
}
else
{
cout<<"Yes"<<endl;
}
return 0;
}