0_0_18018817_5693.cpp:31:5: error: stray '\' in program return (int)(sum\n/2); ^ 0_0_18018817_5693.cpp: In function 'int polya(int)': 0_0_18018817_5693.cpp:31:22: error: expected ')' before 'n' return (int)(sum\n/2); ^