0_0_13375816_2651.cpp:4:2: error: stray '@' in program 0_0_13375816_2651.cpp: In function 'int fun(int)': 0_0_13375816_2651.cpp:4:14: error: 'y0' was not declared in this scope 0_0_13375816_2651.cpp:4:24: error: expected ')' before numeric constant