Problem:
Score : 200 points

Problem Statement

There is a grid of squares with H horizontal rows and W vertical columns.
The square at the i-th row from the top and the j-th column from the left is represented as (i, j).
Each square is black or white.
The color of the square is given as an H-by-W matrix (a_{i, j}).
If a_{i, j} is ., the square (i, j) is white; if a_{i, j} is #, the square (i, j) is black.

Snuke is compressing this grid.
He will do so by repeatedly performing the following operation while there is a row or column that consists only of white squares:

Operation: choose any one row or column that consists only of white squares, remove it and delete the space between the rows or columns.

It can be shown that the final state of the grid is uniquely determined regardless of what row or column is chosen in each operation.
Find the final state of the grid.

Constraints

1 \leq H, W \leq 100

a_{i, j} is . or #.

There is at least one black square in the whole grid.

Input

Input is given from Standard Input in the following format:

H W
a_{1, 1}...a_{1, W}
:
a_{H, 1}...a_{H, W}

Output

Print the final state of the grid in the same format as input (without the numbers of rows and columns); see the samples for clarity.

Sample Input 1

4 4
##.#
....
##.#
.#.#

Sample Output 1

###
###
.##

The second row and the third column in the original grid will be removed.

Sample Input 2

3 3
#..
.#.
..#

Sample Output 2

#..
.#.
..#

As there is no row or column that consists only of white squares, no operation will be performed.

Sample Input 3

4 5
.....
.....
..#..
.....

Sample Output 3

#

Sample Input 4

7 6
......
....#.
.#....
..#...
..#...
......
.#..#.

Sample Output 4

..#
#..
.#.
.#.
#.#

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

///Bismillahir Rahmanir Rahim

#include<cstdio>
#include<iomanip>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<cctype>
#include<algorithm>
#include<string>
#include<vector>
#include<queue>
#include<map>
#include<set>
#include<sstream>
#include<stack>
#include<list>
#include<iostream>
#include<assert.h>
#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")

/**Define file I/O **/
#define f_input freopen("input.txt","r",stdin)
#define f_output freopen("output.txt","w",stdout)

/**Define memory set function**/
#define mem(x,y) memset(x,y,sizeof(x))
#define CLEAR(x) memset(x,0,sizeof(x))

/**Define function and object**/
#define pb push_back
#define Sort(v) sort(v.begin(),v.end())
#define RSort(v) sort(v.rbegin(),v.rend())
#define CSort(v,C) sort(v.begin(),v.end(),C)
#define all(v) (v).begin(),(v).end()
#define sqr(x) ((x)*(x))
#define find_dist(a,b) sqrt(sqr(a.x-b.x)+sqr(a.y-b.y))

/**Define constant value**/
#define ERR 1e-9
#define pi (2*acos(0))
#define PI 3.141592653589793

/**Define input**/
#define scanint(a) scanf("%d",&a)
#define scanLLD(a) scanf("%lld",&a)
#define scanstr(s) scanf("%s",s)
#define scanline(l) scanf(" %[^\n]",l)
#define scandouble(d) scanf("%lf",&d)
#define scanchar(c) scanf("%c",&c)

/**Define Bitwise operation**/
#define check(n, pos) (n & (1ll<<(pos)))
#define biton(n, pos) (n | (1ll<<(pos)))
#define bitoff(n, pos) (n & ~(1ll<<(pos)))

/**Define color**/
enum {WHITE,GREY,BLACK};

/**Sync off with stdio**/
#define __ cin.sync_with_stdio(false);\
           cin.tie();

/**Debug tools**/
#define what_is(x) cerr<<(#x)<<" is "<<x<<endl
using namespace std;

/**Typedef**/
typedef vector<int> vint;
typedef vector< vint > vint2D;
typedef vector<string> vstr;
typedef vector<char>vchar;
typedef vector< vchar >vchar2D;
typedef queue<int> Qi;
typedef queue< Qi > Qii;
typedef map<int,int> Mii;
typedef map<string,int> Msi;
typedef map<int,string> Mis;
typedef stack<int> stk;
typedef pair<int,int> pp;
typedef pair<int, pp > ppp;
typedef long long int ll;
ll inf=1e18;

/**Template & structure**/

template<class T>T gcd(T a,T b){return b == 0 ? a : gcd(b, a % b);}

template<typename T>T lcm(T a, T b) {return a / gcd(a,b) * b;}

template<typename T>T last_bit(T n) { return n & 1; }

template<class T>T big_mod(T n,T p,T m){if(p==0)return (T)1;T x=big_mod(n,p/2,m);x=(x*x)%m;if(p&1)x=(x*n)%m;return x;}

template<class T>T modInv(T a, T m){T x, y; extgcd(a, m, x, y); x %= m; while (x < 0){x += m;} return x;}

template<class T> T extgcd(T a,T b,T& x,T& y){if(b==0){x=1;y=0;return a;}else{int g=extgcd(b,a%b,y,x);y-=a/b*x;return g;}}

template<class T>T multiplication(T n,T p,T m){if(p==0)return (T)0;T x=multiplication(n,p/2,m);x=(x+x)%m;if(p&1)x=(x+n)%m;return x;}

template<class T>T my_pow(T n,T p){if(p==0)return 1;T x=my_pow(n,p/2);x=(x*x);if(p&1)x=(x*n);return x;} ///n to the power p

template <class T> double getdist(T a, T b){return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));}/// distance between a & b

template <class T> T extract(string s, T ret) {stringstream ss(s); ss >> ret; return ret;}/// extract words or numbers from a line

template <class T> string tostring(T n) {stringstream ss; ss << n; return ss.str();}/// convert a number to string

template<class T> T Mod(T n,T m) {return (n%m+m)%m;} ///For Positive Negative No.

template<class T> T MIN3(T a,T b,T c) {return min(a,min(b,c));} /// minimum of 3 number

template<class T> T MAX3(T a,T b,T c) {return max(a,max(b,c));} ///maximum of 3 number

template <class T> void print_vector(T &v){int sz=v.size();if(sz)cout<<v[0];for(int i = 1; i < sz; i++)cout << ' '<<v[i];cout<<"\n";}/// prints all elements in a vector

bool isVowel(char ch){ ch=toupper(ch); if(ch=='A'||ch=='U'||ch=='I'||ch=='O'||ch=='E') return true; return false;}

bool isConsonant(char ch){if (isalpha(ch) && !isVowel(ch)) return true; return false;}

template <class R> R Josephus(R n,R k){R ans=1;for(R i=2;i<=n;i++)ans=(ans+k-1)%i+1;return ans;}

template <class R> R toitent_Phi2(R a){R result = a;for(R i=2;i*i<=a;i++){if(a%i==0) result=result-result/i;while(a%i==0) a=a/i;}if(a>1) result=result-result/a;return result;}

template <typename T> T Angle(T x1,T y1,T x2, T y2){ return atan( double(y1-y2) / double(x1-x2));}


//namespace debug{
//    int sum(){return 0;}
//    template<typename T,typename... Args> T sum(T a,Args... args) {return a+sum(args...);}
//    void print(){cout<<"\n";return;}template<typename T, typename... Args>void print(T a,Args... args){cout<<a<<" ";print(args...);}
//}


/**Direction**/
///int dx[8] = {0, 1, 1, 1, 0, -1, -1, -1};int dy[8] = {1, 1, 0, -1, -1, -1, 0, 1}; ///8 Direction
///int dx[4] = {1, 0, -1, 0};int dy[4] = {0, 1, 0, -1}; ///4 Direction
///int dx[]={2,1,-1,-2,-2,-1,1,2};int dy[]={1,2,2,1,-1,-2,-2,-1};///Knight Direction
///int dx[]={-1,-1,+0,+1,+1,+0};int dy[]={-1,+1,+2,+1,-1,-2}; ///Hexagonal Direction


/******************************End******************************/

#define mxn 109
ll row[mxn];
ll col[mxn];
ll n,m;
string s[mxn];

ll rcheck(ll r){
    for(ll i=0;i<s[r].size();i++){
        if(s[r][i]=='#'){
            return 1;
        }
    }

    return -1;
}

ll ccheck(ll c){
    for(ll i=0;i<n;i++){
        if(s[i][c]=='#'){
            return 1;
        }
    }

    return -1;
}

int main()
{
    __;

    ll T,t;
    ll i,j,k;
    ll q;

    cin>>n>>m;
    for(i=0;i<n;i++){
        cin>>s[i];
    }

    for(i=0;i<n;i++){
        row[i]=rcheck(i);
    }

    for(i=0;i<m;i++){
        col[i]=ccheck(i);
    }

    for(i=0;i<n;i++){
        if(row[i]==-1) continue;

        for(j=0;j<m;j++){
            if(col[j]==-1) continue;

            cout<<s[i][j];
        }
        cout<<"\n";
    }


    return 0;
}