OJ Board

when my program used

while (scanf("%d%d", &n, &m) == 2 && n && m) {...}

to read the data, i got WA

but when i use

while (scanf("%d%d", &n, &m), n) {...}

or

while (scanf("%d%d", &n, &m) == 2 && n) {...}

i've got AC !!

could M equal ZERO ??

notice 1 ? M ? (N^2-N)/2 !!

could anyone give me ...