/in/foo.cc: In function 'int main()':
/in/foo.cc:56:11: warning: unused variable 'j' [-Wunused-variable]
     rei i,j,k;
           ^
/in/foo.cc:56:13: warning: unused variable 'k' [-Wunused-variable]
     rei i,j,k;
             ^
/in/foo.cc:77:11: warning: 'mi' may be used uninitialized in this function [-Wmaybe-uninitialized]
       s[i]=mi;mm+=a[i+l]-a[i-1];
       ~~~~^~~