View Compilation Error

0_0_9855882_21727.cpp:4: error: `main' must return `int'
0_0_9855882_21727.cpp: In function `int main(...)':
0_0_9855882_21727.cpp:8: error: `$r' undeclared (first use this function)
0_0_9855882_21727.cpp:8: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_9855882_21727.cpp:8: error: `$y' undeclared (first use this function)
0_0_9855882_21727.cpp:8: error: `$t' undeclared (first use this function)