22 lines
370 B
C++
22 lines
370 B
C++
#include<cstdio>
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#include<algorithm>
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using namespace std;
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int n,m,p;
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inline int gcd(int a,int b)
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{
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int t;
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while(b) { t=b; b=a%b; a=t; }
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return a;
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}
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int main()
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{
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#ifdef local
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freopen("pro.in","r",stdin);
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#endif
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scanf("%d%d%d",&n,&m,&p);
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double S=m*p*0.5,I=p+gcd(n,m)+gcd(abs(n-p),m);
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// printf("S=%lf I=%lf\n",S,I);
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printf("%d\n",int(S+1-I*0.5+0.5));
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return 0;
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}
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