404 Not Found
#include <cstdio>
#include <vector>
using namespace std;
int a, b;
vector<vector<char> > v;
int dfs(int x, int y){
int _x = x + 1, _y = y + 1, m = 0;
if(_x < a && y < b){
if(v[_x][y] == 0) m += dfs(_x, y);
}
if(x < a && _y < b){
if(v[x][_y] == 0) m += dfs(x, _y);
}
if(x == a - 1 && y == b - 1){
m += 1;
}
return m;
}
int main()
{
while(scanf("%d %d\n", &a, &b), a && b){
int n;
scanf("%d\n", &n);
v = vector<vector<char> >(a, vector<char>(b, 0));
for(int i = 0; i < n; i++){
int x, y;
scanf("%d %d\n", &x, &y);
v[x - 1][y - 1] = 1;
}
printf("%d\n", dfs(0, 0));
}
return 0;
}