/in/foo.cc: In function 'int main()':
/in/foo.cc:9:11: warning: unused variable 'm' [-Wunused-variable]
     int n,m,i,j,f,ant;
           ^
/in/foo.cc:9:15: warning: unused variable 'j' [-Wunused-variable]
     int n,m,i,j,f,ant;
               ^
/in/foo.cc:9:19: warning: unused variable 'ant' [-Wunused-variable]
     int n,m,i,j,f,ant;
                   ^~~