#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_skip() while(*rp++>=48) #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(){ rd_init(); rd_skip(); int z=0; int b=0,c=0; while(c=*rp++,c!=10){ z+=b!=c; b=c; } wt1(z); _exit(0); }