/in/foo.cc: In function 'int s2(int)':
/in/foo.cc:9:7: warning: 'n' may be used uninitialized in this function [-Wmaybe-uninitialized]
  n/=10;
       ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:9:7: warning: 'n' may be used uninitialized in this function [-Wmaybe-uninitialized]
/in/foo.cc:6:13: note: 'n' was declared here
     for(int n;n>0;){
             ^
/in/foo.cc:9:7: warning: 'n' may be used uninitialized in this function [-Wmaybe-uninitialized]
  n/=10;
       ^
/in/foo.cc:6:13: note: 'n' was declared here
     for(int n;n>0;){
             ^