#pragma GCC optimize("Ofast") #pragma GCC target("avx2") #define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);}) #define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;}) #define wt(v) ({ulong _z=v;do*--wp=_z%10+48;while(_z/=10);}) #define wt1(v) ({char wbuf[64],*wp=wbuf+sizeof wbuf;wt(v);write(1,wp,wbuf+sizeof wbuf-wp);}) typedef unsigned long ulong; int main(){ char rbuf[64]; read(0,rbuf,sizeof rbuf); char*rp=rbuf; int A=rd(); int B=rd(); int a=rd(); int b=rd(); while(a%B!=b){ a+=A; } wt1(a); _exit(0); }