/in/foo.cc: In function 'int main()':
/in/foo.cc:5:12: warning: unused variable 'mmin' [-Wunused-variable]
  int a,b,n,mmin,i,j,s,k;
            ^~~~
/in/foo.cc:5:21: warning: unused variable 's' [-Wunused-variable]
  int a,b,n,mmin,i,j,s,k;
                     ^
/in/foo.cc:5:23: warning: unused variable 'k' [-Wunused-variable]
  int a,b,n,mmin,i,j,s,k;
                       ^