View Compilation Error

0_0_5254723_4711.c:2: error: syntax error before '&' token
0_0_5254723_4711.c: In function `extgcd':
0_0_5254723_4711.c:5: error: `b' undeclared (first use in this function)
0_0_5254723_4711.c:5: error: (Each undeclared identifier is reported only once
0_0_5254723_4711.c:5: error: for each function it appears in.)
0_0_5254723_4711.c:7: error: `x' undeclared (first use in this function)
0_0_5254723_4711.c:8: error: `y' undeclared (first use in this function)
0_0_5254723_4711.c:9: error: `a' undeclared (first use in this function)