1 #include<iostream>
 2 #include<algorithm>
 3 #include<cstdio>
 4 #include<climits>
 5 #include<cstring>
 6 using namespace std;
 7 int map[502][502];
 8 bool vis[502][502];
 9 int n,m,k;
10 int sum=0;
11 int amount=0;
12 void dfs(int x,int y)
13 {
14     vis[x][y]=true;
15     amount+=1;
16     if(amount==sum-k)
17     {
18         return;
19     }
20     if(!vis[x-1][y]&&map[x-1][y]&&amount!=sum-k)
21     {
22         dfs(x-1,y);
23     }
24     if(!vis[x+1][y]&&map[x+1][y]&&amount!=sum-k)
25     {
26         dfs(x+1,y);
27     }
28     if(!vis[x][y-1]&&map[x][y-1]&&amount!=sum-k)
29     {
30         dfs(x,y-1);
31     }
32     if(!vis[x][y+1]&&map[x][y+1]&&amount!=sum-k)
33     {
34         dfs(x,y+1);
35     }
36     return;
37 }
38 int main()
39 {
40     
41     scanf("%d%d%d",&n,&m,&k);
42     memset(map,0,sizeof(map));
43     memset(vis,false,sizeof(vis));
44     for(int i=1;i<=n;i++)
45     {
46         getchar();
47         for(int j=1;j<=m;j++)
48         {
49             char c=getchar();
50             if(c==‘#‘)
51             {
52                 map[i][j]=0;
53             }
54             else
55             {
56                 map[i][j]=1;
57                 sum+=1;
58             }
59         }
60     }
61     for(int i=1;i<=n&&amount!=sum-k;i++)
62     {
63         for(int j=1;j<=m;j++)
64         {
65             if(map[i][j])
66             {
67                 dfs(i,j);
68                 break;
69             }
70         }
71     }
72     for(int i=1;i<=n;i++)
73     {
74         for(int j=1;j<=m;j++)
75         {
76             if(!map[i][j])
77             {
78                 printf("#");
79             }
80             else
81             {
82                 if(vis[i][j])
83                 {
84                     printf(".");
85                 }
86                 else
87                 {
88                     printf("X");
89                 }
90             }
91         }
92         printf("\n");
93     }
94     return 0;
95 }