View Compilation Error

0_0_30382097_32416.cpp:1:366: fatal error: GCC4.9.2/lib/gcc/x86_64-w64-mingw32/4.9.2/include/iostream>usin: Invalid argument
 #include<iostream>using namespace std;int main(){    int a[8],t,n,p,q,k,i;    cin>>t;    while(t--)    {        cin>>n;        for(i=1;i<=7;i++)        a[i]=i;        while(n--)        {            cin>>p>>q;            k=a[p];a[p]=a[q];a[q]=k;        }        for(i=1;i<=7;i++)        if(a[i]==2)        {            cout<<i<<endl;            break;        }    }}
                                                                                                                                                                                                                                                                                                                                                                              ^
compilation terminated.