Language: C++

#include<bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    string S;
    cin >> S;
    ll K;
    cin >> K;
    ll siz=S.size();
    if(siz==1){cout<<(K+1)/2<<endl;}
    if(siz==2&&S.at(0)!=S.at(1)){cout<<0<<endl;}
    if(siz==2&&S.at(0)==S.at(1)){cout<<K<<endl;}
    if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
    if(siz==3&&S.at(0)==S.at(1)&&S.at(1)!=S.at(2)){cout<<K<<endl;}
    if(siz==3&&S.at(0)!=S.at(1)&&S.at(1)==S.at(2)){cout<<K<<endl;}
    else{ll X=0;
    ll counter=0;
    for(ll i=0;i<siz-1;i++){
        if(S.at(i)==S.at(i+1)){counter++;
        }
        else{
            X+=(counter+1)/2;
            counter=0;
        }
    ;}
    X+=(counter+1)/2;
    //cout<<X<<endl;
    if(S.at(0)!=S.at(siz-1)){
        cout<<X*K<<endl;
    }
    else if(counter==1&&S.at(0)!=S.at(1)&&S.at(0)==S.at(siz-1)){cout<<X*K<<endl;}
    else cout<<X*K+K-1<<endl;}
    return 0;
}  


Compiler output:
a.cc: In function 'int main()':
a.cc:14:60: error: no match for 'operator*' (operand types are 'std::string' {aka 'std::__cxx11::basic_string<char>'} and 'll' {aka 'long long int'})
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                           ~^~
      |                                                           | |
      |                                                           | ll {aka long long int}
      |                                                           std::string {aka std::__cxx11::basic_string<char>}
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:1:
/usr/include/c++/14/complex:400:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const complex<_Tp>&, const complex<_Tp>&)'
  400 |     operator*(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:400:5: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::complex<_Tp>'
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/complex:409:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const complex<_Tp>&, const _Tp&)'
  409 |     operator*(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:409:5: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::complex<_Tp>'
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/complex:418:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const _Tp&, const complex<_Tp>&)'
  418 |     operator*(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:418:5: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   mismatched types 'const std::complex<_Tp>' and 'll' {aka 'long long int'}
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166:
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'll' {aka 'long long int'}
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'll' {aka 'long long int'}
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/valarray:1198:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__multiplies, _Tp>::result_type> std::operator*(const valarray<_Tp>&, const valarray<_Tp>&)'
 1198 | _DEFINE_BINARY_OPERATOR(*, __multiplies)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1198:1: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::valarray<_Tp>'
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/valarray:1198:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__multiplies, _Tp>::result_type> std::operator*(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1198 | _DEFINE_BINARY_OPERATOR(*, __multiplies)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1198:1: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::valarray<_Tp>'
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^
/usr/include/c++/14/valarray:1198:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__multiplies, _Tp>::result_type> std::operator*(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1198 | _DEFINE_BINARY_OPERATOR(*, __multiplies)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1198:1: note:   template argument deduction/substitution failed:
a.cc:14:61: note:   mismatched types 'const std::valarray<_Tp>' and 'll' {aka 'long long int'}
   14 |     if(siz==3&&S.at(0)==S.at(1)&&S.at(1)==S.at(2)){cout<<(S*K+1/2)<<endl;}
      |                                                             ^