#include "bits/stdc++.h" using namespace std; int m,n,t,r=0; char map1[105][105]; bool pd(int x,int y){ if(map1[x][y]=='#') t--; if(map1[x+1][y]=='#') t--; if(map1[x][y+1]=='#') t--; if(map1[x+1][y+1]=='#') t--; if(t==0||map1[x][y]!='#'&&map1[x+1][y]!='#'&&map1[x][y+1]!='#'&&map1[x+1][y+1]!='#')return true; else return false; } int main(){ cin>>m>>n>>t; for(int i=1;i<=m;i++){ for(int j=1;j<=n;j++){ cin>>map1[i][j]; } }for(int i=1;i<n;i++) for(int j=1;j<m;j++) if(pd(i,j)) { cout<<"-1"; return 0; } for(int i=1;i<=m;i++){ for(int j=1;j<=n;j++){ if(map1[i][j]=='*'&&map1[i-1][j]=='#'&&map1[i][j-1]=='+')r++; } } cout<<r; }