/in/foo.cc: In function 'int main()':
/in/foo.cc:18:31: error: 'abs' was not declared in this scope
    if(((w==11||l==11)&&abs(l-w)>=2)||((w>11)&&(abs(l-w)==2))){
                               ^
/in/foo.cc:18:31: note: suggested alternative:
In file included from /in/foo.cc:3:0:
/usr/include/c++/6/cmath:103:5: note:   'std::abs'
     abs(_Tp __x)
     ^~~
/in/foo.cc:32:31: error: 'abs' was not declared in this scope
    if(((w==21||l==21)&&abs(l-w)>=2)||((w>21)&&(abs(l-w)==2))){
                               ^
/in/foo.cc:32:31: note: suggested alternative:
In file included from /in/foo.cc:3:0:
/usr/include/c++/6/cmath:103:5: note:   'std::abs'
     abs(_Tp __x)
     ^~~