/in/foo.c: In function 'main':
/in/foo.c:6:9: error: expected expression before '%' token
   scanf(%f, %f,&a, &b);
         ^
/in/foo.c:7:3: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   if(a<b);
   ^~
/in/foo.c:8:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
   {printf("%f\n",a);
   ^
/in/foo.c:10:3: error: 'else' without a previous 'if'
   else
   ^~~~