C++ :

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <climits>
#include <cstring>
#include <string>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <vector>
#include <list>
#include <ext/rope>
#define rep(i,m,n) for(i=m;i<=n;i++)
#define rsp(it,s) for(set<int>::iterator it=s.begin();it!=s.end();it++)
#define vi vector<int>
#define pii pair<int,int>
#define mod 1000000007
#define inf 0x3f3f3f3f
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ll long long
#define pi acos(-1.0)
const int maxn=1e2+10;
const int dis[4][2]={{0,1},{-1,0},{0,-1},{1,0}};
using namespace std;
using namespace __gnu_cxx;
ll gcd(ll p,ll q){return q==0?p:gcd(q,p%q);}
ll qpow(ll p,ll q){ll f=1;while(q){if(q&1)f=f*p;p=p*p;q>>=1;}return f;}
int n,m,k,ans,vis[maxn][maxn],poe[maxn][maxn];
char a[maxn][maxn];
struct node
{
    int x,y,now,vis;
    node(int a,int b,int c,int d)
    {
        x=a,y=b,now=c,vis=d;
    }
    bool operator<(const node&p)const
    {
        return vis>p.vis;
    }
};
void bfs(int f,int g)
{
    node init(f,g,k,1);
    priority_queue<node>p;
    p.push(init);
    vis[f][g]=1;poe[f][g]=k;
    while(!p.empty())
    {
        node q=p.top();p.pop();
        int x=q.x,y=q.y;
        for(int i=0;i<4;i++)
        {
            int l=x+dis[i][0],r=y+dis[i][1];
            if(l>=0&&l<n&&r>=0&&r<m)
            {
                if(a[l][r]=='#'&&q.now&&(!vis[l][r]||vis[l][r]>vis[x][y]+3||poe[l][r]<poe[x][y]-1))
                {
                    node u(l,r,q.now-1,q.vis+3);
                    poe[l][r]=q.now-1;
                    vis[l][r]=vis[x][y]+3;
                    p.push(u);
                }
                if(a[l][r]=='.'&&(!vis[l][r]||vis[l][r]>vis[x][y]+1||poe[l][r]<poe[x][y]))
                {
                    node u(l,r,q.now,q.vis+1);
                    poe[l][r]=q.now;
                    vis[l][r]=vis[x][y]+1;
                    p.push(u);
                }
                if(a[l][r]=='E')ans=min(q.vis,ans);
            }
        }
    }
}
int main()
{
    int i,j;
    scanf("%d%d%d",&n,&m,&k);
    ans=1e9;
    rep(i,0,n-1)scanf("%s",a[i]);
    rep(i,0,n-1)rep(j,0,m-1)
        if(a[i][j]=='B'){bfs(i,j);goto loop;}
    loop:;
    if(ans!=1e9)printf("%d\n",ans);
    else puts("-1");
    //system ("pause");
    return 0;
}