int solve(){
MaxQueue Q;
for (int i = 1; i <= K; i++){
if (d[i] == 1){
for (int y = 1; y <= M; y++){
Q.clear();
for (int x = N, ii = 1; x >= 1; x--, ii++){
while(Q.size() > t[i] - s[i] + 1) Q.pop();
if (grid[x][y] == 'x'){Q.clear(); continue;}
dp[i][x][y] = dp[i - 1][x][y];
if (Q.size()) dp[i][x][y] = max(dp[i][x][y], Q.max() + ii);
if (dp[i - 1][x][y]) Q.push(dp[i - 1][x][y] - ii);
else Q.push(-0x1f1f1f1f);
}
}
}else if (d[i] == 2){
for (int y = 1; y <= M; y++){
Q.clear();
for (int x = 1, ii = 1; x <= N; x++, ii++){
while(Q.size() > t[i] - s[i] + 1) Q.pop();
if (grid[x][y] == 'x'){Q.clear(); continue;}
dp[i][x][y] = dp[i - 1][x][y];
if (Q.size()) dp[i][x][y] = max(dp[i][x][y], Q.max() + ii);
if (dp[i - 1][x][y]) Q.push(dp[i - 1][x][y] - ii);
else Q.push(-0x1f1f1f1f);
}
}
}else if (d[i] == 3){
for (int x = 1; x <= N; x++){
Q.clear();
for (int y = M, ii = 1; y >= 1; y--, ii++){
while(Q.size() > t[i] - s[i] + 1) Q.pop();
if (grid[x][y] == 'x'){Q.clear(); continue;}
dp[i][x][y] = dp[i - 1][x][y];
if (Q.size()) dp[i][x][y] = max(dp[i][x][y], Q.max() + ii);
if (dp[i - 1][x][y]) Q.push(dp[i - 1][x][y] - ii);
else Q.push(-0x1f1f1f1f);
}
}
}else if (d[i] == 4){
for (int x = 1; x <= N; x++){
Q.clear();
for (int y = 1, ii = 1; y <= M; y++, ii++){
//cout << Q.size() << ", " << t[i] << ", " << s[i] << "=>" << (Q.size() ? Q.max(): 0) << endl;
while(Q.size() > t[i] - s[i] + 1) Q.pop();
if (grid[x][y] == 'x'){Q.clear(); continue;}
dp[i][x][y] = dp[i - 1][x][y];
if (Q.size()) dp[i][x][y] = max(dp[i][x][y], Q.max() + ii);
if (dp[i - 1][x][y]) Q.push(dp[i - 1][x][y] - ii);
else Q.push(-0x1f1f1f1f);
}
}
}
}
int ans = 0;
for (int x = 1; x <= N; x++){
for (int y = 1; y <= M; y++){
ans = max(ans, dp[K][x][y]);
}
}
return ans - 1;
}
