/in/foo.c: In function 'main':
/in/foo.c:5:17: error: 'a' undeclared (first use in this function)
    5 |     scanf("%d",&a);
      |                 ^
/in/foo.c:5:17: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:8:10: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
    8 |     else if(70<=score&&score<=79);
      |          ^~
/in/foo.c:9:5: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
    9 |     {printf("B\n");}
      |     ^
/in/foo.c:10:5: error: 'else' without a previous 'if'
   10 |     else if(60<=score&&score<=69);
      |     ^~~~
/in/foo.c:10:10: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   10 |     else if(60<=score&&score<=69);
      |          ^~
/in/foo.c:11:5: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   11 |     {printf("C\n");}
      |     ^
/in/foo.c:12:5: error: 'else' without a previous 'if'
   12 |     else if(0<=score&&score<60);
      |     ^~~~
/in/foo.c:12:10: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   12 |     else if(0<=score&&score<60);
      |          ^~
/in/foo.c:13:5: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   13 |     {printf("D\n");}
      |     ^