> #define maxn 33
> #include<string.h>
> #include<stdio.h>
> int cover[maxn*maxn],link[maxn*maxn];
> int n,m,k,num,f[maxn*maxn][maxn*maxn],d[maxn][maxn],use[maxn][maxn];
> void task1()
>  {int t,i,j,x,y;
>   scanf("%d %d %d",&n,&m,&k);
>   memset(f,0,sizeof(f));memset(d,0,sizeof(d));memset(use,0,sizeof(use));
>   for (i=1;i<=k;i++)
>    {
>      scanf("%d %d",&y,&x);
>      use[x][y]=1;
>    }
>   num=0;
>   for (i=1;i<=n;i++)
>    for (j=1;j<=m;j++)
>     if (use[i][j]==0) {num+=1;d[i][j]=num;};
>   for (i=1;i<=n;i++)
>    for (j=1;j<=m;j++)
>     if (use[i][j]==0)
>        { t=d[i][j];
>          if (i-1>=1&&use[i-1][j]==0) f[t][d[i-1][j]]=1;
>          if (j-1>=1&&use[i][j-1]==0) f[t][d[i][j-1]]=1;
>          if (i+1<=n&&use[i+1][j]==0) f[t][d[i+1][j]]=1;
>          if (j+1<=m&&use[i][j+1]==0) f[t][d[i][j+1]]=1;
>        } 
> }
> int find(int i)
>  { int b,q,z;
>    z=0;
>   for(b=1;b<=num;b++)
>    if (f[i][b]==1&&cover[b]==0)
>        {
>          q=link[b];link[b]=i;cover[b]=1;
>          if (q==0||find(q)==0) return(z);
>          link[b]=q;
>        }
>    z=1;
>    return(z);
> }
> void maintask()
> {int i;
>  for (i=1;i<=num;i++)
>   {
>    memset(cover,0,sizeof(cover));
>    find(i);
>   }
> }
> void task2()
>  {int i,z;
>   z=0;
>   
>   for (i=1;i<=num;i++) 
> 	if (link[i]==0) 
> 	{z=1;break;}
>   
>   if (z==1) printf("NO\n");
>      else printf("YES\n");
> }
> void main()
> { 
>   task1();
>   num=n*m-k;
>   maintask();
>   task2();  
> }