Can u help me find the problem in this code

#include
#include
using namespace std;
int main() {
int n,N,deci_num=0;
cin>>n;
for(int i=0;i<=n;i++){
cin>>N;

    int a=0;
    while(N>0){
        int val=N%10;
        deci_num += (val*pow(2,a));
        a++;
        N=N/10;
        

    }

cout<<deci_num<<endl;
}

return 0;

}