#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
#include <unordered_map>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef long double ld;
const ll dim=1e6 + 10;
const ll mod=998244353;
const ll inf=1e18+77;
//#define endl "\n"
#define fi first
#define pb push_back
#define se second
#define vll vector<ll>
ll n,t;
vector<vll> g, vis;
ll a[dim];
ll m;
ll r, c;
queue<pll> q1, q2;
struct state{
ll val, h, v;
};
ll fl=0;
vector<vector<state> > dst;
vector<pll> buf, buf1;
void check(ll x, ll y, ll val, ll h, ll v, ll tp){
if(x<1 || x>r || y<1 || y>c)return;
if(dst[x][y].val<=val)return;
dst[x][y]={val, h, v};
if(tp==0){fl=1; buf.pb({x, y}); q1.push({x, y});}
else{buf1.pb({x, y}); q2.push({x, y});}
}
void check1(ll x, ll y, ll val){
if(x<1 || x>r || y<1 || y>c)return;
if(g[x][y]==1){
check(x, y, val+1, n-1, n-1, 1);
}
else{
check(x, y, val, 0, 0, 0);
}
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//cin>>t;
t=1;
while(t--){
cin>>r>>c>>n;
ll p1, p2, x, y;
//ll u1, u2;
char ch;
cin>>p1>>p2;
cin>>x>>y;
g.assign(r+6, vll(c+6, 0));
vis.assign(r+6, vll(c+6, 0));
dst.assign(r+6, vector<state>(c+6, {r*c+100,0, 0}));
for(int i=1; i<=r; i++) {
for(int j=1; j<=c; j++){
cin>>ch;
g[i][j]=(ch=='#');
// cout<<g[i][j]<<" ";
}
//cout<<endl;
}
check1(p1, p2, 0);
while(q1.size()>0){
fl=0;
auto [u1, u2]=q1.front();
// cout<<u1<<" "<<u2<<endl;
state cur=dst[u1][u2];
// cout<<cur.val<<" "<<cur.h<<" "<<cur.v<<endl;
q1.pop();
if(cur.v>0) {
check(u1 - 1, u2, cur.val, cur.h, cur.v - 1, 0);
check(u1 + 1, u2, cur.val, cur.h, cur.v - 1, 0);
}
if(cur.h>0) {
check(u1, u2 - 1, cur.val, cur.h - 1, cur.v, 0);
check(u1, u2 + 1, cur.val, cur.h - 1, cur.v, 0);
}
if(q1.size()==0){
for(int i=0; i<buf.size(); i++){
u1=buf[i].fi; u2=buf[i].se;
cur=dst[u1][u2];
check1(u1 - 1, u2, cur.val);
check1(u1 + 1, u2, cur.val);
check1(u1, u2 - 1, cur.val);
check1(u1, u2 + 1, cur.val);
}
q1=q2;
buf=buf1;
buf1.clear();
while(q2.size()>0)q2.pop();
}
}
cout<<dst[x][y].val<<endl;
}
return 0;
}
