foo.c: In function 'prime':
foo.c:36:5: error: stray '\243' in program
foo.c:36:5: error: stray '\250' in program
foo.c:36:9: error: expected '(' before 'ans'
foo.c:36:9: warning: statement with no effect [-Wunused-value]
foo.c:36:15: error: expected statement before ')' token