View Compilation Error

0_0_24434916_24788.cpp: In function 'int main()':
0_0_24434916_24788.cpp:33:67: error: 'const struct node' has no member named 'b'
             if(it == s.begin() || x==it->x || y==it->y || (--it)->b >=b)
                                                                   ^
0_0_24434916_24788.cpp:33:71: error: 'b' was not declared in this scope
             if(it == s.begin() || x==it->x || y==it->y || (--it)->b >=b)
                                                                       ^