AC(ez)
#include <bits/stdc++.h>
using namespace std;
int x[5], y[5];
int main(){
int are = 0, cnt = 0, mx = 0;
for (int i = 1; i <= 3; i ++ ) {
cin >> x[i] >> y[i];
are += x[i] * y[i];
mx = max(mx, max(x[i], y[i]));
}
if (are != mx * mx) cout << -1 << endl;
else {
for (int i = 1; i <= 3; i ++ ) {
if (x[i] == mx) cnt ++;
else if (y[i] == mx) {
cnt ++;
swap(x[i], y[i]);
}
}
if (cnt == 3) {
cout << mx << endl;
for (int i = 1; i <= 3; i ++ )
for (int j = 1; j <= y[i]; j ++ ) {
for (int k = 1; k <= mx; k ++ )
cout << (char) ('A' + i - 1);
cout << endl;
}
} else if (cnt == 1) {
cout << mx << endl;
int a, b, c;
if (x[1] == mx) a = 2, b = 3, c = 1;
else if (x[2] == mx) a = 1, b = 3, c = 2;
else a = 1, b = 2, c = 3;
if (x[a] == y[b]) swap(x[b], y[b]);
else if (y[a] == x[b]) swap(x[a], y[a]);
else if (y[a] == y[b]) swap(x[a], y[a]), swap(x[b], y[b]);
for (int i = 1; i <= y[c]; i ++ ) {
for (int j = 1; j <= mx; j ++ )
cout << (char)('A' + c - 1);
cout << endl;
}
for (int j = 1; j <= x[a]; j ++ ) {
for (int k = 1; k <= y[a]; k ++ )
cout << (char)('A' + a - 1);
for (int k = 1; k <= y[b]; k ++ )
cout << (char)('A' + b - 1);
cout << endl;
}
}
}
return 0;
}