/in/foo.c: In function 'main':
/in/foo.c:7:4: warning: implicit declaration of function 'pow' [-Wimplicit-function-declaration]
  c=pow(10,10);
    ^~~
/in/foo.c:7:4: warning: incompatible implicit declaration of built-in function 'pow'
/in/foo.c:7:4: note: include '<math.h>' or provide a declaration of 'pow'
/in/foo.c:7:4: warning: overflow in implicit constant conversion [-Woverflow]