/in/foo.cc: In function 'int main()':
/in/foo.cc:22:34: error: use of 'auto' in lambda parameter declaration only available with -std=c++14 or -std=gnu++14
     auto dfs = [&](int x, int y, auto self) -> int {
                                  ^~~~
/in/foo.cc: In lambda function:
/in/foo.cc:35:67: error: 'self' cannot be used as a function
                     dp[x][y] = max(dp[x][y], 1 + self(tx, ty, self));
                                                                   ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:46:41: error: no match for call to '(main()::<lambda(int, int, int)>) (int&, int&, main()::<lambda(int, int, int)>&)'
             ans = max(ans, dfs(i, j, dfs));
                                         ^
/in/foo.cc:22:48: note: candidate: main()::<lambda(int, int, int)>
     auto dfs = [&](int x, int y, auto self) -> int {
                                                ^~~
/in/foo.cc:22:48: note:   no known conversion for argument 3 from 'main()::<lambda(int, int, int)>' to 'int'