/in/foo.c: In function 'main':
/in/foo.c:8:11: warning: implicit declaration of function 'Fib' [-Wimplicit-function-declaration]
   sum=sum+Fib(i);
           ^~~
/in/foo.c:5:17: warning: unused variable 'm' [-Wunused-variable]
     int k1,k2,n,m,i,sum=0;
                 ^
/in/foo.c:5:15: warning: unused variable 'n' [-Wunused-variable]
     int k1,k2,n,m,i,sum=0;
               ^
/in/foo.c:8:6: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
   sum=sum+Fib(i);
   ~~~^~~~~~~~~~~
/in/foo.c: In function 'Fib':
/in/foo.c:15:15: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int a=1, b=1,c;
               ^