1135: paired base chain

#include<string.h>
#include<iostream>
using namespace std;
int main()
{
	char a[256];
	cin.getline(a,256);
	for(int i=0;i<strlen(a);i++)
	{
		if(a[i]=='A')
		{
			cout<<"T";
		 } 
		 else if(a[i]=='T')
		 {
		 	cout<<"A";
		 }
		 else if(a[i]=='C')
		 {
		 	cout<<"G";
		 }
		 else
		 {
		 	cout<<"C";
		 }
	}
	return 0;
 }