/in/foo.cc: In function 'int main()':
/in/foo.cc:16:3: error: expected ';' before 'for'
   for(;j<s;j++)
   ^~~
/in/foo.cc:16:7: warning: statement has no effect [-Wunused-value]
   for(;j<s;j++)
       ^
/in/foo.cc:16:8: error: 'j' was not declared in this scope
   for(;j<s;j++)
        ^