Run id: 115984

Main.cc: In function 'int main()':
Main.cc:8:19: error: 'v' was not declared in this scope
     printf("%.4f",v);
                   ^
Main.cc:6:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%f",&r);
                   ^