Find Substring

Given two strings s and p, determine the starting index of the first occurrence of p in s. If p is not found in s, output -1.

In particular, if p is an empty string, by definition, the answer is 0.

Formally, find the smallest index \( i \) such that \( s[i:i+\text{len}(p)] = p \).

inputFormat

The input consists of two lines:

• The first line contains the string s.
• The second line contains the string p.

outputFormat

Output a single line containing the index of the first occurrence of p in s. If p does not occur in s, output -1.

hello
ll

2