const std = @import("std");

const input = @embedFile("input");

pub fn main() !void {
    // Put this or it doesn't evaluate all branches
    @setEvalBranchQuota(500000);
    const result = comptime findUniqueCharsIdx(14, input);
    const ares = comptime uintEncode(result, 10, "0123456789") catch unreachable;
    _ = std.os.linux.write(1, &ares, 10);
}

fn uintEncode(num: usize, comptime bufflen: usize, comptime charset: []const u8) ![bufflen]u8 {
    // Check if the number is bigger than the maximum possible number
    var pow = comptime std.math.pow(usize, charset.len, bufflen);
    if (num >= pow) unreachable;

    var buff = [_]u8{charset[0]} ** bufflen;

    var num_i: usize = num;
    for (buff) |*pos| {
        pow /= charset.len;
        pos.* = charset[@divTrunc(num_i, pow)];

        num_i %= pow;
    }

    return buff;
}
fn findUniqueCharsIdx(_n: usize, string: []const u8) usize {
    for (input) |_, i| {
        const n = _n - 1;
        // Start searching at fourth character
        if (i < n) continue;
        if (i > input.len - n) break;

        const chars: []const u8 = string[i-n..i+1];

        chars: for (chars) |char_1, j| {
            for (chars) |char_2, k| {
                // Don't check the same character, or the ones that we already checked
                if (j <= k) continue;
                //std.debug.print("{c},{c}\n", .{char_1, char_2});
                if (char_1 == char_2) {
                    // Don't check anymore
                    break :chars;
                }
            }
        } else {
            // If no repeats have been found
            // i is the current character index in the input (i+1 if we count from 1)
            return i + 1;
        }
    }
    return 0;
}