Language: C++

#include<bits/stdc++.h>                                                                                                                                                                                         using namespace std;                                                                                                                                                                                            #define lli long long                                                                                   #define all(i) i.begin(),i.end()                                                                        #define rall(i) i.rbegin(),i.rend()                                                                     #define rep0(i,j) for(lli i=0;i<j;i++)                                                                  #define rep1(i,j) for(lli i=1;i<=j;i++)                                                                 #define rep0d(i,j) for(lli i=j-1;i>=0;i--)                                                              #define MAX 1000000007                                                                                                                                                                                          int main(){                                                                                                     int n,m,l;                                                                                              cin >> n >> m;                                                                                          if(0<n&&n<10&&0<m&&m<10)cout << n*m;                                                                    else cout << -1;                                                                                                                                                                                        }

Compiler output:
a.cc:1:209: warning: extra tokens at end of #include directive
    1 | #include<bits/stdc++.h>                                                                                                                                                                                         using namespace std;                                                                                                                                                                                            #define lli long long                                                                                   #define all(i) i.begin(),i.end()                                                                        #define rall(i) i.rbegin(),i.rend()                                                                     #define rep0(i,j) for(lli i=0;i<j;i++)                                                                  #define rep1(i,j) for(lli i=1;i<=j;i++)                                                                 #define rep0d(i,j) for(lli i=j-1;i>=0;i--)                                                              #define MAX 1000000007                                                                                                                                                                                          int main(){                                                                                                     int n,m,l;                                                                                              cin >> n >> m;                                                                                          if(0<n&&n<10&&0<m&&m<10)cout << n*m;                                                                    else cout << -1;                                                                                                                                                                                        }
      |                                                                                                                                                                                                                 ^~~~~
/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