foo.c:1:1: warning: data definition has no type or storage class
    1 | a=input("请输入一个数");
      | ^
foo.c:1:1: warning: type defaults to 'int' in declaration of 'a' [-Wimplicit-int]
foo.c:1:3: warning: implicit declaration of function 'input' [-Wimplicit-function-declaration]
    1 | a=input("请输入一个数");
      |   ^~~~~
foo.c:1:3: error: initializer element is not constant
foo.c:2:1: warning: data definition has no type or storage class
    2 | b=input("请输入一个数");
      | ^
foo.c:2:1: warning: type defaults to 'int' in declaration of 'b' [-Wimplicit-int]
foo.c:2:3: error: initializer element is not constant
    2 | b=input("请输入一个数");
      |   ^~~~~
foo.c:3:1: warning: data definition has no type or storage class
    3 | c=input("请输入一个数");
      | ^
foo.c:3:1: warning: type defaults to 'int' in declaration of 'c' [-Wimplicit-int]
foo.c:3:3: error: initializer element is not constant
    3 | c=input("请输入一个数");
      |   ^~~~~
foo.c:4:1: error: expected identifier or '(' before 'if'
    4 | if (a+b>=c and a+c>=b and b+c>=a)
      | ^~

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