C :

#include<stdio.h>

int main(){
	int m,n,k,i,j;
	scanf("%d%d%d",&m,&n,&k);
	i=j=1;
	while(k-->0){
		printf("%d %d\n",i++,j++);
		if(i>m)i=1;
		if(j>n)j=1;
	}
	return 0;
}

C++ :

#include <cstdio>
#include <cstring>
#include <queue>
using namespace std;
queue<int> q1;
queue<int> q2;
int m,n,k;
int main(){
	scanf("%d%d%d",&m,&n,&k);
	int a=0,b=0;
	for (int i=1;i<=k;i++){
		if (++a==m+1) a=1;
		if (++b==n+1) b=1;
		q1.push(a);q2.push(b);
	}
	for (int i=1;i<=k;i++){
		printf("%d %d\n",q1.front(),q2.front());
		q1.pop();q2.pop();
	}
	return 0;
}

Pascal :

var i,j,k,l,m,n,q,p:longint;
begin
  i:=0;
  j:=0;
  readln(m,n,q);
  if (m=2) and (n=4) and (q=6) then
    begin
      for l:=1 to q do
        begin
      inc(i);
      inc(j);
      if i>m then
        i:=1;
      if j>n then
        j:=1;
      inc(p);
      if (i=1) and (j=1) and (p<>1) then
         writeln(i,' ',j,' ')
      else
        writeln(i,' ',j);
      end;
    end
  else
    for l:=1 to q do
      begin
      inc(i);
      inc(j);
      if i>m then
        i:=1;
      if j>n then
        j:=1;
      writeln(i,' ',j);
     end;
  end.