View Compilation Error

0_0_31475226_24859.cpp: In function 'void mark(int)':
0_0_31475226_24859.cpp:31:4: error: expected '(' before '%' token
  if%2
    ^
0_0_31475226_24859.cpp:31:5: error: expected '}' at end of input
  if%2
     ^