/in/foo.cc: In function 'int main()':
/in/foo.cc:14:9: error: expected primary-expression before ';' token
  a=a*20%;
         ^
/in/foo.cc:15:9: error: expected primary-expression before ';' token
  b=b*30%;
         ^
/in/foo.cc:16:9: error: expected primary-expression before ';' token
  c=c*50%;
         ^