function Main(input){
    min = 1e18
    max = -1e18
    let abc = "abcdefghijklmnopqrstuvwxyz".split("")
    let ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split("")
    let f = 3
    if(f == 0){
      input = parseInt(input.trim())
    }
    if(f == 1){
      input = input.trim().split("\n").map((a)=>parseInt(a))
    }
    if(f == 2){
      input = input.trim().split("\n").map((a)=>a.split(" ").map((b)=>parseInt(b)))
    }
    res = 0
   input =  input.trim().split("\n")
   let [h,w,d] = input.shift().split(" ").map((a)=>parseInt(a))
   let s = input.map((a)=>a.split(""))
   hlist = []
   for(let i = 0;i<h;i++){
     for(let j = 0;j<w;j++){
       if(s[i][j] == "H"){
         hlist.push([i,j])
       }
     }
   }
   map = []
   for(let i = 0;i<h;i++){
     map.push(new Array(w).fill(-1))
   }
   let bfs = []
   for(let i = 0;i<hlist.length;i++){
     map[hlist[i][0]][hlist[i][1]] = 0
     bfs.push([hlist[i][0],hlist[i][1],0])
   }
   let a = 0
   while(a<bfs.length){
     if(bfs[a][2] == 2){
       //console.log(map.join("\n"))
     }
     y = bfs[a][0]
     x = bfs[a][1]
     //console.log(y,x)
    
     
     let list = [[-1,0],[0,1],[1,0],[0,-1]]
     for(let i = 0;i<4;i++){
       let ny = y+list[i][0]
       let nx = x+list[i][1]
       
       //console.log(ny,nx)
       if(0<=ny && ny<h && 0<=nx && nx<w && map[ny][nx] == -1 && s[ny][nx] == "."){
         
         
         bfs.push([ny,nx,bfs[a][2]+1])
          map[ny][nx] = bfs[a][2]+1
       }
     }
     a++
   }
   count = 0
   for(let i = 0;i<h;i++){
     for(let j = 0;j<w;j++){
       if(map[i][j] != -1){
         if(map[i][j] <= d){
           count ++
         }
       }
     }
   }
   console.log(count)
   function dfs(y,x,depth){
    
   }
  }
  Main(require("fs").readFileSync(0, "utf8"));
  
//ここより上は定型文です。