Main.cc: In function ‘int read()’: Main.cc:14:5: warning: this ‘while’ clause does not guard... [-Wmisleading-indentation] while ((c = getchar()) == ' ' || c == '\n' || c == '\r'); ^~~~~ Main.cc:15:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘while’ if (c == '-') flag = true; ^~ Main.cc: In function ‘int main()’: Main.cc:49:21: error: expected primary-expression before ‘/’ token while (l <= r){ / 2; ^