foo.cc: In function 'int main()':
foo.cc:5:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |         cin>>a;
      |         ^~~
      |         std::cin
iostream:60:18: note: 'std::cin' declared here
foo.cc:9:5: error: 'else' without a previous 'if'
    9 |     else if(a>3)
      |     ^~~~
foo.cc:9:10: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
    9 |     else if(a>3)
      |          ^~
foo.cc:11:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   11 |         b=10+a*2.5;
      |         ^
foo.cc:12:9: error: 'else' without a previous 'if'
   12 |         else if(a<=3)
      |         ^~~~

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