/in/foo.c: In function 'main':
/in/foo.c:5:25: error: expected expression before '<=' token
    5 |         if(score>=80 && <=100){
      |                         ^~
/in/foo.c:8:30: error: expected ';' before '}' token
    8 |                 printf("B\n")
      |                              ^
      |                              ;
    9 |         }else if(score>=60 && score<70){
      |         ~                     
/in/foo.c:11:18: error: expected expression before ')' token
   11 |         }else if()score>=0 && score<60{
      |                  ^
/in/foo.c:11:19: warning: statement with no effect [-Wunused-value]
   11 |         }else if()score>=0 && score<60{
      |                   ^~~~~