View Compilation Error

0_0_23692662_21654.cpp: In function 'int main()':
0_0_23692662_21654.cpp:13:61: error: assignment of read-only location '*(std::dec + ((sizetype)i))'
   for (int i=1;i<n;i++) {cin>>deci[i];if (deci[i]==2) dec[i]=-1;}
                                                             ^
0_0_23692662_21654.cpp:13:61: error: cannot convert 'int' to 'std::ios_base&(std::ios_base&)' in assignment