foo.c: In function 'main':
foo.c:8:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(i=0;i<=3;i++)
  ^~~
foo.c:16:4: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    for(i=0;i<=5;i++)
    ^~~
foo.c:7:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%c",&ch[i]); 
     ^~~~~~~~~~~~~~~~~~
foo.c:18:20: warning: iteration 5 invokes undefined behavior [-Waggressive-loop-optimizations]
     printf("%4c",ch[i]);
                  ~~^~~
foo.c:16:4: note: within this loop
    for(i=0;i<=5;i++)
    ^~~

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