In file included from /in/Compile/check.cpp:7:
/in/sokoban.hpp:45:20: error: implicit conversion changes signedness: 'const int' to 'unsigned long' [-Werror,-Wsign-conversion]
        if (boxX + dx[i] >= grid.size() || boxY + dy[i] >= grid[0].size()) continue;
                 ~ ^~~~~
/in/sokoban.hpp:45:51: error: implicit conversion changes signedness: 'const int' to 'unsigned long' [-Werror,-Wsign-conversion]
        if (boxX + dx[i] >= grid.size() || boxY + dy[i] >= grid[0].size()) continue;
                                                ~ ^~~~~
/in/sokoban.hpp:105:21: error: implicit conversion changes signedness: 'const int' to 'unsigned long' [-Werror,-Wsign-conversion]
            if (x + dx[i] >= grid.size() || y + dy[i] >= grid[0].size()) continue;
                  ~ ^~~~~
/in/sokoban.hpp:105:49: error: implicit conversion changes signedness: 'const int' to 'unsigned long' [-Werror,-Wsign-conversion]
            if (x + dx[i] >= grid.size() || y + dy[i] >= grid[0].size()) continue;
                                              ~ ^~~~~
/in/sokoban.hpp:179:29: error: implicit conversion changes signedness: 'const int' to 'unsigned long' [-Werror,-Wsign-conversion]
                    if (x + dx[i] >= current.grid.size() || y + dy[i] >= current.grid[0].size() ||
                          ~ ^~~~~
/in/sokoban.hpp:179:65: error: implicit conversion changes signedness: 'const int' to 'unsigned long' [-Werror,-Wsign-conversion]
                    if (x + dx[i] >= current.grid.size() || y + dy[i] >= current.grid[0].size() ||
                                                              ~ ^~~~~
6 errors generated.
/in/Compile/Makefile:16: recipe for target 'main' failed
make: *** [main] Error 1