#include<bits/stdc++.h>

 #define pa pair<int,int>

 #define CLR(a,x) memset(a,x,sizeof(a))

 using namespace std;

 typedef long long ll;

 const int maxn=1e3+;

 inline ll rd(){

     ll x=;char c=getchar();int neg=;

     while(c<''||c>''){if(c=='-') neg=-;c=getchar();}

     while(c>=''&&c<='') x=x*+c-'',c=getchar();

     return x*neg;

 }

 struct Q{

     int q[maxn][],h,t;

     inline void psh(int x,int y,bool b){

         while(h&&h>=t&&(b?q[h][]<=x:q[h][]>=x)) h--;

         q[++h][]=x,q[h][]=y;

         if(!t) t=h;

     }

     inline int pop(int lim){

         while(h>t&&q[t][]<=lim) t++;

         return q[t][];

     }

     inline void clr(){h=t=;}

 }ama[maxn],ami[maxn],bma,bmi;

 int N,A,B,arr[maxn][maxn];

 int main(){

     //freopen("","r",stdin);

     int i,j,k;

     A=rd(),B=rd();N=rd();

     for(i=;i<=A;i++){

         for(j=;j<=B;j++)

             arr[i][j]=rd();

     }

     int ans=2e9;

     for(i=;i<=A;i++){

         for(j=;j<=B;j++){

             ama[j].psh(arr[i][j],i,);

             ami[j].psh(arr[i][j],i,);

         }

         if(i>=N){

             bma.clr(),bmi.clr();

             for(j=;j<=B;j++){

                 int a=ama[j].pop(i-N),b=ami[j].pop(i-N);

                 bma.psh(a,j,);

                 bmi.psh(b,j,);

                 if(j>=N) ans=min(ans,bma.pop(j-N)-bmi.pop(j-N));

             }

         }

     }

     printf("%d\n",ans);

     return ;

 }