#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
char s[255], ch;
short n, i, j, cod;
int main()
{
cin >> s;
n=strlen(s);
for (i=0; i<n-1; ++i)
{
if (s[i]==s[i+1] || (int)s[i]-(int)s[i+1]==32 || (int)s[i]-(int)s[i+1]==-32 )
{
while (s[i]==s[i+1] || (int)s[i]-(int)s[i+1]==32 || (int)s[i]-(int)s[i+1]==-32)
{
for (j=i; j<n-1; ++j) s[j]=s[j+1];
--n; s[n]=0;
}
for (j=i; j<n-1; ++j) s[j]=s[j+1];
--n; s[n]=0;
i=-1;
}
}
cout << s;
}
