#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int H,W;
ll K;


void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>H>>W>>K;
	int cy=0,cx=0,dy=1,dx=1;
	int step=0;
	while(step==0||(cy||cx||dy!=1||dx!=1)) {
		step++;
		if(cy+dy<0||cy+dy>=H) dy=-dy;
		else cy+=dy;
		if(cx+dx<0||cx+dx>=W) dx=-dx;
		else cx+=dx;
	}
	K%=2*step;
	map<pair<int,int>,int> M;
	while(K) {
		M[{cy,cx}]^=1;
		if(cy+dy<0||cy+dy>=H) dy=-dy;
		else cy+=dy;
		if(cx+dx<0||cx+dx>=W) dx=-dx;
		else cx+=dx;
		K--;
	}
	FOR(y,H) {
		FOR(x,W) {
			if(M[{y,x}]) cout<<"#";
			else cout<<".";
		}
		cout<<endl;
	}
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}