我在按顺序执行程序时收到以下错误。

"C:\Program Files\JetBrains\CLion 2019.2.3\bin\cmake\win\bin\cmake.exe" --build C:\Users\two43\CLionProjects\cse\cmake-build-debug --target cse -- -j 2
[ 25%] Linking CXX executable cse.exe
CMakeFiles\cse.dir\build.make:114: recipe for target 'cse.exe' failed
c:/mingw/bin/../lib/gcc/mingw32/8.2.0/../../../../mingw32/bin/ld.exe: CMakeFiles\cse.dir/objects.a(lecture-2.cpp.obj): in function `main':
C:/Users/two43/CLionProjects/cse/lecture-2.cpp:24: multiple definition of `main'; CMakeFiles\cse.dir/objects.a(lecture-1.cpp.obj):C:/Users/two43/CLionProjects/cse/lecture-1.cpp:19: first defined here
collect2.exe: error: ld returned 1 exit status
mingw32-make.exe[3]: *** [cse.exe] Error 1
mingw32-make.exe[2]: *** [CMakeFiles/cse.dir/all] Error 2
CMakeFiles\Makefile2:74: recipe for target 'CMakeFiles/cse.dir/all' failed
mingw32-make.exe[1]: *** [CMakeFiles/cse.dir/rule] Error 2
CMakeFiles\Makefile2:81: recipe for target 'CMakeFiles/cse.dir/rule' failed
mingw32-make.exe: *** [cse] Error 2
Makefile:117: recipe for target 'cse' failed

以下是CMakeLists.txt文件：

cmake_minimum_required(VERSION 3.15)
project(cse)
set(CMAKE_CXX_STANDARD 17)
add_executable(cse main.cpp lecture-1.cpp lecture-2.cpp)