Give you a integer number N (1 ≤ n ≤ 2 ∗ 10^100). Please compute
Give the last digit of S to me.
Input file consists of several N ’s, each N a line. It is ended with N = 0.
For each N give a line containing only one digit, which is the last digit of S.
範例輸入 1
1 2 3 0
範例輸出 1
1 5 2
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