PKU [2521]. How much did the businessman lose. [AC]

#include <stdio.h> int main() { int N, M, P, C; while(1) { scanf("%d%d%d%d", &N, &M, &P, &C); if((N == 0) && (M == 0) && (P == 0) && (C == 0) ) { return 0; } printf("%d\n", N - M + P); } return 0; }

In PKU Judge system.

... 지군 혹사시키는 것 같아서 미안하구려.