/*

     记忆化搜索(DP+DFS)：dp[i][j] 表示第i到第j个字符，最少要加多少个括号

         dp[x][x] = 1 一定要加一个括号；dp[x][y] = 0, x > y;

         当s[x] 与 s[y] 匹配，则搜索 (x+1, y-1); 否则在x~y-1枚举找到相匹配的括号，更新最小值

 */

 #include <cstdio>

 #include <algorithm>

 #include <cmath>

 #include <iostream>

 #include <cstring>

 using namespace std;

 const int MAXN = 1e2 + ;

 const int INF = 0x3f3f3f3f;

 int dp[MAXN][MAXN];

 int pos[MAXN][MAXN];

 char s[MAXN];

 void DFS(int x, int y)

 {

     if (dp[x][y] != -)    return ;

     if (x > y)        {dp[x][y] = ;    return ;}

     if (x == y)    {dp[x][y] = ;    return ;}

     dp[x][y] = INF;

     if ((s[x]=='(' && s[y]==')') || (s[x]=='[' && s[y]==']'))

     {

         pos[x][y] = -;

         DFS (x+, y-);

         dp[x][y] = dp[x+][y-];

     }

     for (int i=x; i<y; ++i)

     {

         DFS (x, i);    DFS (i+, y);

         int cur = dp[x][i] + dp[i+][y];

         if (cur < dp[x][y])

         {

             dp[x][y] = cur;        pos[x][y] = i;

         }

     }

 }

 void print(int x, int y)

 {

     if (x > y)    return ;

     if (x == y)

     {

         if (s[x] == '(' || s[y] == ')')    printf ("()");

         else    printf ("[]");

         return ;

     }

     if (pos[x][y] == -)

     {

         printf ("%c", s[x]);

         print (x+, y-);

         printf ("%c", s[y]);

     }

     else

     {

         print (x, pos[x][y]);    print (pos[x][y]+, y);

     }

 }

 int main(void)        //URAL 1183 Brackets Sequence

 {

     //freopen ("O.in", "r", stdin);

     while (scanf ("%s", s+) == )

     {

         int len = strlen (s+);

         memset (dp, -, sizeof (dp));

         memset (pos, , sizeof (pos));

         DFS (, len);

         print (, len);    puts ("");

     }

     return ;

 }