Language: C++

#include<bits/stdc++.h>                                                                                                 using namespace std;                                                                                                    int main(){                                                                                                                     int N,K,X,Y;                                                                                                                                                                                                                                    cin>>N;                                                                                                                 cin>>K;                                                                                                                 cin>>X;                                                                                                                 cin>>Y;                                                                                                                                                                                                                                         int fst_p,sec_d,sec_p,sum;                                                                                                                                                                                                                      fst_p = K * X//最初金額                                                                                                                                                                                                                         sec_d = N - (K+1);//金額が変化する日数                                                                                  sec_p = sec_d * Y;//変化した後の金額                                                                                                                                                                                                            sum = fst_p + sec_p;                                                                                                                                                                                                                            cout>>sum>>endl;                                                                                                        return 0;                                                                                                       }   

Compiler output:
a.cc:1:121: warning: extra tokens at end of #include directive
    1 | #include<bits/stdc++.h>                                                                                                 using namespace std;                                                                                                    int main(){                                                                                                                     int N,K,X,Y;                                                                                                                                                                                                                                    cin>>N;                                                                                                                 cin>>K;                                                                                                                 cin>>X;                                                                                                                 cin>>Y;                                                                                                                                                                                                                                         int fst_p,sec_d,sec_p,sum;                                                                                                                                                                                                                      fst_p = K * X//最初金額                                                                                                                                                                                                                         sec_d = N - (K+1);//金額が変化する日数                                                                                  sec_p = sec_d * Y;//変化した後の金額                                                                                                                                                                                                            sum = fst_p + sec_p;                                                                                                                                                                                                                            cout>>sum>>endl;                                                                                                        return 0;                                                                                                       }
      |                                                                                                                         ^~~~~
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/14/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
(.text+0x17): undefined reference to `main'
collect2: error: ld returned 1 exit status