思路：
轮廓线dp入门题
#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pi acos(-1.0)
#define LL long long
//#define mp make_pair
#define pb push_back
#define ls rt<<1, l, m
#define rs rt<<1|1, m+1, r
#define ULL unsigned LL
#define pll pair<LL, LL>
#define pii pair<int, int>
#define mem(a, b) memset(a, b, sizeof(a))
#define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fopen freopen("in.txt", "r", stdin);freopen("out.txt", "w", stout);
//head const int N = ;
LL dp[][<<N], n, m, cur;
void update(int a, int b) {
if(b & (<<m))dp[cur][b^(<<m)] += dp[-cur][a];
}
int main() {
while(~ scanf("%d%d", &n, &m) && n && m) {
if(n < m) swap(n, m);
mem(dp, );
cur = ;
dp[][(<<m)-] = ;
for (int i = ; i < n; i++) {
for (int j = ; j < m; j++) {
cur ^= ;
mem(dp[cur], );
for (int k = ; k < (<<m); k++) {
update(k, k<<);
if(i && !(k & (<<m-))) update(k, (k<<)^(<<m)^);
if(j && !(k & )) update(k, (k<<)^);
} }
}
printf("%lld\n", dp[cur][(<<m)-]);
}
return ;
}