> #include <iostream>
> //#include <fstream>
> #include <string>
> using namespace std;
> string b[101][101],cs;
> int a[101][101],i,j,k,len,p;
> int main()
> {
>   //  ifstream cin("in.txt");
>   //  ofstream cout("out.txt");
>     while(getline(cin,cs))
>     {
>         len = cs.length();
>         if(len==0)
>         {
>             cout<<endl;
>             continue;
>         }    
>         for(i=0; i<len; i++)
>         {    
>             for(j=0; j<=len; j++)
>             {
>                 b[i][j] = "";
>             }
>             a[i+1][i] = 0;
>             a[i][i] = 1;
>             if(cs[i]=='['||cs[i]==']')
>             {
>                 b[i][i] = "[]";
>             }
>             if(cs[i]=='('||cs[i]==')')
>             {
>                 b[i][i] = "()";
>             }               
>         }    
>         for(p=1; p<len; p++)
>         {
>             for(i=0; i<len-p; i++)
>             {
>                 j = i + p;
>                 a[i][j] = 1000;
>                 if(cs[i]=='['&&cs[j]==']' || cs[i]=='('&&cs[j]==')')
>                 {
>                     if(a[i+1][j-1]<a[i][j])
>                     {
>                         a[i][j] = a[i+1][j-1];
>                         int x = b[i][j].length();
>                     //    char c = b[i][j][0],ch = b[i][j][x-1];
>                     //    cout<<"c = "<<c<<"  ch = "<<ch<<endl;
>                         if(cs[i]=='[')
>                         {
>                             b[i][j] = '['+b[i+1][j-1]+']';
>                         }    
>                         else
>                         {
>                             b[i][j] = '('+b[i+1][j-1]+')';
>                         }    
>                     }
>                 //    continue;    
>                 }
>                 if(cs[i]=='(' || cs[i]=='[')
>                 {
>                     char c = cs[i]=='('?')':']';
>                     if(a[i+1][j]+1<a[i][j])
>                     {
>                         a[i][j] = a[i+1][j]+1;
>                         b[i][j] = cs[i]+b[i+1][j]+c; 
>                     }
>                //    continue; 
>                 }    
>                 if(cs[j]==')' || cs[j]==']')
>                 {
>                     char c1 = (cs[j]==')'?'(':'[');
>                     if(a[i][j-1]+1<a[i][j])
>                     {
>                         a[i][j] = a[i][j-1]+1;
>                         b[i][j] = c1+b[i][j-1]+cs[j];
>                     }
>                //     continue;    
>                 }
>                 for(k=i; k<j; k++)
>                 {
>                     if(a[i][k]+a[k+1][j]<a[i][j])
>                     {
>                         a[i][j] = a[i][k]+a[k+1][j];
>                         b[i][j] = b[i][k]+b[k+1][j];
>                     }                        
>                 }            
>             }    
>         }
>         cout<<b[0][len-1]<<endl;   
>     }
>   //  cin.close();
>   //  cout.close();   
>     return 0;
> }