1141

/*
动态规划


*/

// include file
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <cctype>
#include <ctime>

#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <bitset>

#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <set>
#include <list>
#include <functional>

using namespace std;

// typedef
typedef long long LL;
typedef unsigned long long ULL;

// 
#define read freopen("in.txt","r",stdin)
#define write freopen("out.txt","w",stdout)
#define FORi(a,b,c) for(int i=(a);i<(b);i+=c)
#define FORj(a,b,c) for(int j=(a);j<(b);j+=c)
#define FORk(a,b,c) for(int k=(a);k<(b);k+=c)
#define FORp(a,b,c) for(int p=(a);p<(b);p+=c)
#define FORii(a,b,c) for(int ii=(a);ii<(b);ii+=c)
#define FORjj(a,b,c) for(int jj=(a);jj<(b);jj+=c)
#define FORkk(a,b,c) for(int kk=(a);kk<(b);kk+=c)

#define FF(i,a)    for(int i=0;i<(a);i++)
#define FFD(i,a)   for(int i=(a)-1;i>=0;i--)

#define Z(a) (a<<1)
#define Y(a) (a>>1)

const double eps = 1e-6;
const double INFf = 1e100;
const int INFi = 2000000000;
const LL INFll = (LL)1<<62;
const double Pi = acos(-1.0);

template<class T> inline T sqr(T a){return a*a;}
template<class T> inline T TMAX(T x,T y)
{
	if(x>y) return x;
	return y;
}
template<class T> inline T TMIN(T x,T y)
{
	if(x<y) return x;
	return y;
}
template<class T> inline void SWAP(T &x,T &y)
{
	T t = x;
	x = y;
	y = t;
}
template<class T> inline T MMAX(T x,T y,T z)
{
	return TMAX(TMAX(x,y),z);
}
template<class T> inline T MMIN(T x,T y,T z)
{
	return TMIN(TMIN(x,y),z);
}


// code begin
char in[110];
int N;
int DP[110][110][2];
bool equ(char c1,char c2)
{
	if(c1=='(' && c2==')')
		return true;
	if(c1=='[' && c2==']')
		return true;
	return false;
}
void dis(char c)
{
	if(c==')' || c=='(')
	{
		printf("()");
		return;
	}
	if(c==']' || c=='[')
	{
		printf("[]");
		return;
	}
}
void dfs(int l,int r)
{
	if(l>r) return;
	if(DP[l][r][0]==0)
	{
		FORi(l,r+1,1)
			printf("%c",in[i]);
		return;
	}
	if(l==r)
	{
		dis(in[l]);
		return;
	}
	if(  DP[l][r][1]==0 )
	{
		printf("%c",in[l]);
		dfs(l+1,r-1);
		printf("%c",in[r]);
	}
	else
	{
		dfs(l,l+DP[l][r][1]-1);
		dfs(l+DP[l][r][1],r);
	}
}
int main()
{
	read;
	write;
	scanf("%s",in);
	N = strlen(in);
	memset(DP,0,sizeof(DP));
	FORi(0,N,1)
	{
		DP[i][i][0] = 1;
		DP[i][i][1] = 1;
	}
	FORi(1,N,1)
	{
		FORj(0,N,1)
		{
			if(j+i>=N) break;
			DP[j][j+i][0] = INFi;
			FORk(j,j+i,1)
			{
				if(DP[j][k][0]+DP[k+1][j+i][0]<DP[j][j+i][0])
				{
					DP[j][j+i][0] = DP[j][k][0]+DP[k+1][j+i][0];
					DP[j][j+i][1] = k-j+1;
				}
			}
			if( equ(in[j],in[j+i]) && DP[j+1][j+i-1][0]<DP[j][j+i][0])
			{
				DP[j][j+i][0] = DP[j+1][j+i-1][0];
				DP[j][j+i][1] = 0;
			}	

			//printf("%d %d %d %d\n",j,j+i,DP[j][j+i][0],DP[j][j+i][1]);
		}
	}
	
	dfs(0,N-1);
	printf("\n");
	return 0;
}