/in/foo.c: In function 'main':
/in/foo.c:6:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
     ^
/in/foo.c:10:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%f %f",&a,&b);
         ^