#include <stdio.h> int main(int argc, const char * argv[]) { int a; int b; int an; while (1) { scanf("%d",&a); scanf("%d",&b); an=b%a; if (an==0) { an=a-1; } else { an--; } printf("%d",an); } return 0; }

while(scanf("%d %d",&a,&b)!=EOF)