View Compilation Error

0_0_5052361_13749.c:7: error: syntax error before '/' token
0_0_5052361_13749.c:11: error: syntax error before "cal_sum"
0_0_5052361_13749.c: In function `cal_sum':
0_0_5052361_13749.c:16: error: syntax error before "res"
0_0_5052361_13749.c:51: error: `res' undeclared (first use in this function)
0_0_5052361_13749.c:51: error: (Each undeclared identifier is reported only once
0_0_5052361_13749.c:51: error: for each function it appears in.)
0_0_5052361_13749.c: In function `main':
0_0_5052361_13749.c:60: error: syntax error before "res"
0_0_5052361_13749.c:66: error: `res' undeclared (first use in this function)