View Compilation Error

0_0_33561157_1537.cpp: In function 'bool operator<(so, so)':
0_0_33561157_1537.cpp:21:22: error: expected ';' at end of input
  return x1.a + x1.b %3
                      ^
0_0_33561157_1537.cpp:21:22: error: expected '}' at end of input