View Compilation Error

0_0_27828965_27761.cpp:3:7: error: 'a' was not declared in this scope
 int f(a,b,n)
       ^
0_0_27828965_27761.cpp:3:9: error: 'b' was not declared in this scope
 int f(a,b,n)
         ^
0_0_27828965_27761.cpp:3:11: error: 'n' was not declared in this scope
 int f(a,b,n)
           ^
0_0_27828965_27761.cpp:3:12: error: expression list treated as compound expression in initializer [-fpermissive]
 int f(a,b,n)
            ^
0_0_27828965_27761.cpp:4:1: error: expected ',' or ';' before '{' token
 {
 ^
0_0_27828965_27761.cpp: In function 'int main()':
0_0_27828965_27761.cpp:16:30: error: 'f' cannot be used as a function
         printf("%d\n",f(a,b,n));
                              ^