View Compilation Error

0_0_2057075_32549.c: In function `main':
0_0_2057075_32549.c:16: error: `o' undeclared (first use in this function)
0_0_2057075_32549.c:16: error: (Each undeclared identifier is reported only once
0_0_2057075_32549.c:16: error: for each function it appears in.)
0_0_2057075_32549.c:17: error: syntax error before '}' token