View Compilation Error

0_0_6031815_1908.c: In function `main':
0_0_6031815_1908.c:31: error: `ed' undeclared (first use in this function)
0_0_6031815_1908.c:31: error: (Each undeclared identifier is reported only once
0_0_6031815_1908.c:31: error: for each function it appears in.)
0_0_6031815_1908.c:31: error: syntax error at end of input