/in/foo.c: In function 'main':
/in/foo.c:5:36: warning: unused variable 'c' [-Wunused-variable]
  int price,demand,number,min_price,c,able,cost=0;
                                    ^
/in/foo.c:5:6: warning: unused variable 'price' [-Wunused-variable]
  int price,demand,number,min_price,c,able,cost=0;
      ^
/in/foo.c:8:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&demand,&number);
   ^
/in/foo.c:12:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d%d",&arr[i-1][0],&arr[i-1][1]);
    ^
/in/foo.c:36:23: warning: '_min' may be used uninitialized in this function [-Wmaybe-uninitialized]
           arr[_min][1]=0;
                       ^
/in/foo.c:34:21: warning: 'able' may be used uninitialized in this function [-Wmaybe-uninitialized]
        demand=demand-able;
                     ^