def partN(input_data, step): for i, window in enumerate( [input_data[i:i + step] for i in range(len(input_data) - step)]): if len(set(window)) == step: return i + step if __name__ == '__main__': with open('./input.txt') as f: inp = f.read().strip() print(partN(inp, 4)) print(partN(inp, 14))