Wazifa for obtaining a good result in examinations.?

Asalamwalikum. What had happened was that I had known a Wazifa for exams that I had to read 197 times. I have now forgotten the Dua to read as I had learned more Duas with very similar wordings. Please if somebody can help me and tell me what the Dua was. I would greatly appreciate it. Please do not think I do not study and only depend on Duas, I do study but I did not have the confidence I had when I had last given my exams with the Wazifa